Back up the other end - there is a nice tempo to this half now - Arsenal win a free-kick on the left side of the penalty area. Willian clips the ball in and Gabriel, who somehow ends up unmarked, stoops to head wide.

Steve Bruce will be furious at the ease at which the Arsenal defender was allowed to find space.

Newcastle look sharper since half-time and try to stretch Arsenal again with a quick break forward.

Allan Saint-Maximin sprints forward as Calum Chambers - who only came on as a sub a few moments ago - scampers in pursuit and does enough to stop the Frenchman playing in Callum Wilson.

Hope Chambers managed to warm up enough before being throw on for the injured David Luiz. My hamstrings couldn't have coped.

Arsenal win a corner after a deflected shot from Pierre-Emerick Aubameyang but Newcastle clear and look to pounce on the counter.

Mat Ryan, in a sweeper-keeper position patented by Manuel Neuer, initially looks like he might get caught in possession, but quickly rearranges his feet to play out of trouble.

Pat Nevin
Former Chelsea and Scotland winger on BBC Radio 5 Live

We understand and applaud what the fans have done [previously]. I walked through with Chelsea fans before the Brighton game when the Super League thing all imploded and you kind of smiled and thought "well done".

Fan power is great, but it has to be used in the right way and at the moment I'm not convinced by that. They can make the point from outside just as well.

Gary Flintoff
BBC Radio 5 live reporter at Old Trafford

We've got more fans inside the ground and this time they've actually come from the back of the stand and one or two have decided to roll down the tarpaulins towards the pitch.

At the moment its about 20 or 30 fans, many of whom with hoods up with masks on, and once again they're chanting "we want Glazers out".

We're being advised to move away from where we are broadcasting from.

Granit Xhaka... you lucky boy. The Arsenal left-back bodychecks Sean Longstaff - seemingly rather cynically - but escapes a yellow card. Just the stern eye from Mike Dean. "Last chance buddy..."

That's exactly what they do. Matt Ritchie's left foot is again Newcastle's most dangerous weapon, but his teasing cross is cut out before Callum Wilson can get on the end of it.

Poor David Luiz. He limps off and looks disconsolate. Newcastle might want to test Calum Chambers and that rearranged Arsenal defence as soon as possible...

This does not look good for David Luiz. The Arsenal defender, back after missing a spell through injury, seems to have pulled his hamstring after playing the ball.

He knows his afternoon is done. Calum Chambers prepares to come on.

Pfff, not much in this. Gabriel tumbles in his own box as he tries to shepherd a long Newcastle ball back to Mat Ryan under pressure from Callum Wilson.

A centre-half should never be going down like that. Martin Keown will be tutting in disgust.

More space for Matt Ritchie on the left. Can he deliver? Nope. The Newcastle left wing-back's pained expression says it all.

Newcastle tend to perform much better in the second half of matches - and boy do they need that today.

The home side begin the second half more on the front foot. Encouraging stuff.

What an extraordinary stat this is from our friends at Opta!

Willian is the only outfield player for Arsenal who didn't attempt a shot in the first half against Newcastle.

Off we go again!

Things are much calmer at St James' Park, although the home fans would no doubt have expressed some anger at their team's first-half performance.

"Get on the groovy train" pumps out as the players return to the pitch. Been nothing groovy so far from Steve Bruce's men.

Remarkably, the Sky pundits on the platform described by Gary Flintoff are carrying on with their live broadcast. They look shocked at what they have seen.

Here are a few of the images from what happened earlier...

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Gary Flintoff
BBC Radio 5 live reporter at Old Trafford

Image source, Getty Images

In these times it's quite bizarre to see supporters inside the stadium. Around 200 fans broke through the megastore end, many wearing the green and yellow scarves, the original colours of Newton Heath, and many wearing baseball caps with their faces covered.

They chanted for the Glazers to get out of their club and many gathered in front of the Sky Sports presentation platform, chanting towards the pundits. One fan did decide to throw a flare into the direction of that platform.

A few fans did pick up some chairs and threw them as they made their way onto the pitch. Ground staff are still removing litter off the pitch.

Five or six actually made it down the tunnel towards the dressing rooms. The club tells us that dressing rooms weren't breached and no fans made it inside, but we've just seen a young man led out of the tunnel and down the pitch. The word is that fans have now been cleared from the interior of the stadium.

The next tricky moment is when the two coaches arrive, because the suggestion is that the fans will do their very best to make a barrier to stop the teams actually making their way on site here.

We'll have to see how that plays out in the next half hour or so.

Simon Stone
BBC Sport at Old Trafford

Hundreds of fans have been on the pitch and many are now exiting through gates across a road that normally allows the team buses through.

No media are being allowed through the gates as normal until the situation is cleared.

Referee Michael Oliver and former United skipper Gary Neville were amongst those whose vehicles were surrounded as they entered the stadium.

There was no trouble and both were allowed through amid a lot of anti-Glazer chanting.