Jon Donnison
BBC News, Sydney

reports that Man Haron Monis is well known to the Australian police. The cleric is currently on bail for being an accessory to the murder of his ex-wife and is facing more than 40 sexual and indecent assault charges. Below is an archive image of the suspect.

Image source, EPA

More on the suspect. Man Haron Monis is also described as a self-proclaimed "spiritual healer", who dealt with black magic at in Sydney more than a decade ago, the Sydney Morning Herald reports., external

Man Haron Monis is currently on bail for a string of violent offences and has a conviction for sending offensive letters to the families of deceased Australian soldiers, the BBC's Jon Donnison in Sydney reports.

Police say they believe the man who seized hostages is Man Haron Monis - an Iranian-born cleric who has been granted asylum in Australia.

Mr Dolnik tells the BBC World Service's Newshour programme, external: "If he's alone then he cannot take turns guarding hostages, cannot rest, so as long as this incident stretches out he will become so fatigued that from high-level demands he will start looking for a way out."

Adam Dolnik, a hostage negotiator and Director of Terrorism Studies at the University of Wollongong in Australia, says the fact the gunman is alone and is likely to be tired could be used to negotiator's advantage.

@GavinDFernando in Sydney tweets, external: #IllRideWithYou shows you shouldn't be scared to be Muslim. You should be scared to be racist.

The mother of a man being held hostage tells Australian radio he texted her to say he was inside the Lindt cafe. The woman, identified as Mel, said: "He sent me a message saying 'I'm ok mum can't talk' and I haven't heard anything since."

ABC journalist Nick Dole in Sydney tweets, external: A big group of ambulances & fire trucks assemble near Martin Place, preparing for any scenario. #sydneysiege

The car-sharing service Uber has faced criticism after apparently hiking prices for customers wanting to leave central Sydney. As the crisis unfolded, people in the area faced fees four times normal rates. The company said it had increased prices to encourage drivers into the area. But it later said journeys would be free.

Jon Donnison
BBC News, Sydney

"This massive police operation is still very much under way. We've just been down to the police cordon, about 500 metres away from the Lindt cafe, and there's still a lot of heavily armed police officers in the area. And what police are saying at the moment is they are urging patience, their ultimate goal is to get everyone out safely, and they are saying that might take some time."

BBC Newsbeat has looked at some of the selfies taken at the scene, external - including one using the hashtag #hostagesituationselfie - and the angry responses they have provoked on social media.

tweets, external: There's been movement at the cafe, the gunman moving a hostage past the window, two more hostages change positions. Not much sleep in there

The BBC has put together some of the most powerful images from the siege.

Image source, EPA

@magwood66 in Ballarat, Australia tweets, external: Great to see the no of people joining the #illridewithyou campaign as a result of #sydneysiege . Keep it up Oz and let's hope this is global

This is what the exclusion zone looks like, according to the latest information, as police continue to surround the cafe where the hostages are being held.

tweets:, external Very little movement at the Lindt Cafe. One person, we believe to be the gunman, walking toward back office. He is carrying an iPad

Danielle McGrane, from Dublin, lives in Sydney where she works as a music journalist. She said: "The city feels eerily calm and quiet, especially for this time of year in the lead up to Christmas... Nobody said a word on the train home, it was the quietest train journey I've ever experienced on that line."

In their latest statement, external, police have urged people in Sydney to go about their business as usual on Tuesday. They are continuing to cordon off areas around the cafe and have advised on a number of closures.

tweets: , external11pm and still plenty of onlookers here at Martin Place. All eyes on the cafe door. Praying we'll see more hostages released @9NewsSyd