Image source, AP

Away from the on-field action, there were some unsavoury scenes in several Brazilian cities as the World Cup got under way on Thursday.

Police clashed with protesters - angry at how much the government has spent on preparations for the tournament - in Sao Paulo, Rio de Janeiro and a number of other host cities.

Officers used tear gas on crowds in Sao Paulo hours before Brazil beat Croatia 3-1 in the opening match. Several people were also injured after scuffles broke out in Rio de Janeiro.

David Ornstein
BBC Sport in Salvador

"Spain conducted their official pre-match news conference and final training session before the start of their World Cup title defence against the Netherlands later today.

"It is, of course, a repeat of the 2010 final and a couple of hundred media personnel crammed into a theatre inside Arena Fonte Nova to hear the views of coach Vincent del Bosque, goalkeeper Iker Casillas and midfielder Xavi.

"Casillas opened proceedings by admitting his side are there to be shot at - 'Spain are being seen as the best national squad in the world and any teams playing against us are going to do their very best to beat us' - before insisting that they have the 'ambition, humility and enthusiasm' to 'try to get that second star for our country'."

Should football adopt a review-style system like tennis, American football and other sports?

Your views have been coming in on #bbcworldcup.

Paddy Emmerson: , externalNo red card, No pen, No goal, No DRS for football, I mean we have seen some spectacular failures with the Cricket DRS.

Steve Hynes:, external Simple solution to reduce scandalous refereeing decisions, half the risk and put another referee on the pitch like Australia RL

So what is top of the shop at the top of the hour? These are your headlines at 09:00 BST.

• Croatia defender Dejan Lovren says that referee Yuichi Nishimura's performance in their 3-1 defeat to Brazil last night was a "scandal", adding that the official "should not be at this World Cup".

• Spain midfielder Xavi promises that the defending champions will stay true to their passing style as they embark on their World Cup defence against the Netherlands tonight.

• Global players' union FIFPro have added to criticism of the pitch on which England will play Italy in Manaus on Saturday, saying: "The players deserve a quality playing surface. This isn't the case in Manaus".

Neymar's first World Cup campaign got off to a good start last night. The 22-year-old scored two goals in Brazil's 3-1 tournament-opening win over Croatia.

How a player performs at his first World Cup is not always a reliable indicator of future performance. Diego Maradona had just signed for Barcelona for a world record fee when he arrived at Spain 1982. He failed to live up to his billing though, anonymous in an opening defeat by Belgium and sent off as his side went out to Brazil in the quarter-finals.

Image source, Getty Images

Modern-day footballers are often accused of providing anodyne quotes to the eager media hounds loitering in the tunnel after a match. Not so Dejan Lovren. The Croatia defender didn't hold back when asked about Japanese referee Yuichi Nishimura's decision to award that dubious penalty to Brazil.

"It's a scandal - this referee should not be at this World Cup," says the Southampton man.

"I don't know for what he deserved to be here. It's really disappointing for us because we were playing a good game against a big team. Two billion people I think saw that it was not a penalty. I didn't touch him."

John, Richhill, via text: Some VERY strong words from Croatian coach Niko Kovac. He clearly felt very hard done by, and he and the whole population of Croatia probably do have a point. I wonder what Mr Blatter and FIFA will have to say about his comments? There's never a dull moment in these World Cups!

Nudge, nudge, wink, wink - you heard the latest gossip? If not, all the whispers from Brazil can be found in our daily Gossip Column.

England forward Danny Welbeck, 23, has declared himself fit for Saturday's opener against Italy after a thigh injury. (Guardian)

Uruguay may leave Liverpool striker Luis Suarez, 27, out of their starting line-up to face England in Sao Paulo next week if they win their opening match against Costa Rica. (Times - subscription only)

Cameroon captain Samuel Eto'o, 33, has been criticised for "treason" after being at the centre of strike action by his nation's World Cup squad. (Independent)

Dan Roan
BBC sports news correspondent in Brazil

3.30am in Manaus, just arrived from Sao Paulo. And it feels like a sauna. Came here a few months ago but it feels worse now.

Image source, Gustavo Olivira

Brazil full-back Dani Alves is one of the few members of Luis Felipe Scolari's squad who comes from one of the country's rural areas rather than the more affluent southern states of Rio de Janeiro, Sao Paulo and Minas Gerais.

BBC's Donna Bowater has been to visit his home village of Umbuzeiro, in the state of Bahia, to meet his family and see where the Barcelona star grew up.

Monty, irritated in Bath, via text: I am sick of watching refereeing decisions decide the outcome of a game. Neymar may go on to take the plaudits as tournament top scorer, when the reality is he should have seen red before he had scored even his first. The penalty decision was even worse. If I'm this irritated I can only imagine how Croatians must feel this morning.

Neymar claims Brazil's 3-1 win over Croatia in their opening World Cup match exceeded his dreams. The Barcelona forward scored twice to ensure the tournament hosts got off to a winning start in Group A.

Neymar is seen as key to Brazil's hopes of winning the World Cup on home soil and admitted his relief after coming from behind to win.

"I think I am happier than I ever dreamt, to start with a victory in the World Cup such as this," he says. "The whole team deserves praise for being able to keep calm and turn things around."

England's World Cup-winning rugby union coach Sir Clive Woodward on Twitter:, external Stats prove referees favour home team , not bias but human behaviour, influenced by many things eg. crowd noise, Brazil penalty proves points

Plenty of Croatia fans believe that Neymar should not have been on the pitch to convert a penalty that should never have been given. Might a 'review' or 'challenge' system, like they have in tennis, American football or cricket, help referees get the biggest decision right?

Harry Butcher:, external Would love for managers to have a challenge. Fred dived there and it was not a penalty.

Matthew Underwood:, external Issue with review system is football isn't stop-start, only able to review decisions that stop the game? Controversy will remain.

Orange Peanut:, external Would the ref have overturned his original decision? I doubt it because he could argue it was, then where do we go?

BBC Radio 5 live

Former World Cup referee Graham Poll says Japanese official Yuichi Nishimura's decision to award Brazil's crucial penalty against Croatia was clearly a "mistake".

"It was a penalty because he gave it - but I don't think he was right to give it," the Englishman tells BBC Radio 5 live. "I cannot even see why he was tempted because it was a minimal touch.

"But he is a good referee and he handled the game well under pressure. He was relaxed throughout so I didn't understand why he made the error he made."

It's easy for referees to make a mistake in a World Cup, eh Graham?

Image source, Getty Images

So how good were the hosts last night?

They had 61% of possession completed 85% of 452 passes and registered six shots on target.

While Neymar stole the headlines by scoring Brazil's first two goals, the Barcelona playmaker lost the ball on 23 occasions - more than any other player.

Room for improvement...

Sticky tape - check. Wall tack - check. Scissors - check. All you need now is a downloadable World Cup wallchart. Fear not friends, those nice chaps and chapesses from Match of the Day Kickabout, the little sibling of our legendary highlights show, have obliged.

Click this link, make sure your printer has plenty of ink and paper, then get going.

Image source, Getty Images

Japanese football fans joined in the criticism of compatriot Yuichi Nishimura after the referee's controversial decisions, slating his performance on social media.

@sanadamasayuki2 commented:, external "It's a tough job for us dithering Japanese"

@tonbuhin tweeted:, external "Oh dear, if Brazil win the World Cup the whole world will say Nishimura was the MVP (most valuable player)."

Good point Jonty - should Neymar even been on the pitch to convert Brazil's decisive second goal? Former England striker Alan Shearer, who didn't mind a physical battle in his playing days, doesn't think so.

"He was very lucky," says the Match of the Day pundit. "If it was any other team, or even player, he would have seen red."

Do you agree with Jonty and Alan? Text 81111, use #bbcworldcup on Twitter or by posting on our Facebook page.

Jonty, London, via text: What could have been a good game ruined by the ref and Croatia can feel cheated. Neymar should have been off, never a pen and Croatia's goal should have stood. Influenced by the home crowd? I think so.