It comes days after striker Pierre-Emerick Aubameyang was stripped of the captaincy following his "latest disciplinary breach".

"They showed exactly what I expect from them," said Arteta.

"They showed total unity with the team. We are building a project and building a project without the people is impossible.

"They were fully focused. They wanted to show how strong we are as a team. The performance, the attitude and the commitment they showed today is exactly what we are as a club."

In an eventful match, Alexandre Lacazette - wearing the captain's armband for Arsenal - had a penalty saved, while West Ham defender Vladimir Coufal was sent off.

Coufal was shown a second booking in conceding the penalty as he was judged to have fouled Lacazette in the box.

He had been booked in the first half when his flailing arm caught defender Kieran Tierney in the face.

"I'm really pleased with the performance, the quality, the energy, the passion and the crowd. We had some really good moments," added Arteta.

"It was a really difficult team to play against. They have a lot of solutions and are a threat in many, many ways. I think we controlled them pretty well.

"It was a big game for us to obviously have the capacity to go above them and move fourth. It was a statement. We had been pretty strong at home, so we needed to put a good performance in against a good team and I think we did that."

Aubameyang was not part of the squad - and asked whether he will feature away to Leeds in the Premier League on Saturday, Arteta said they will "discuss it in the near future".

On Lacazette wearing the armband against West Ham, he added: "He has taken it with pride and commitment and I'm really happy with how he played.

"You see how he acts with the younger players. He's not a selfish player."

'It was the right decision by Arteta' - analysis

Former midfielder Danny Murphy on Match of the Day: "Arteta is used to dealing with problems and he's just given himself a whole lot more - in a really good way.

"He's got these terrific young players who are competing for places, pushing each other, playing with energy and freedom. Arsenal just grew in stature - it was terrific to watch.

"The fact is, if you're the captain of a big club like Arsenal and you keep breaking the rules and setting a bad example, you can't be captain - it's very easy.

"It was the right decision by Arteta and well done to him."

'Anthony Taylor got this one right'

West Ham, who dropped out of the top four as a result of this defeat, have picked up just one win in their past six Premier League games.

They have suffered injuries to key defenders Angelo Ogbonna, Kurt Zouma and Aaron Cresswell in recent weeks and manager David Moyes admitted the team may have "hit a period of suffering".

"We didn't play well and Arsenal played well tonight," he added.

"We just might have hit a period where we're suffering a little with injuries and we're just a bit short in our forward play. We have to improve on that if we can.

"We never really got up to the speed of the game from the start and Arsenal showed real intensity."

Moyes also said referee Anthony Taylor was right to award a penalty when Coufal caught Lacazette on the follow-through after his challenge inside the box.

"Over the weekend, we had some really soft penalty kicks but I think Anthony Taylor might have got this one right," said Moyes. "Vladimir Coufal should have got better contact on the ball.

"I still feel the referee could have not given it because of the contact but the follow-through is probably more the reason for it. I don't think it was that difficult a tackle to make."