Penelope Cruz kept Johnny Depp on top of his game during Pirates Of The Caribbean film shoot

Working with Penelope Cruz kept Johnny Depp on his toes as he filmed the fourth Pirates Of The Caribbean film, he said at its UK premiere in London.

Depp, who plays Captain Jack Sparrow in Pirates Of The Caribbean: On Stranger Tides, was greeted by screams from hundreds of hysterical fans who had packed into London's Westfield shopping centre.

Wearing a charcoal suit and teal shirt, Depp signed autographs on the blue carpet, lit to resemble the sea.

Cruz, who was pregnant during the shoot, stars as Captain Jack's old flame Angelica, a female pirate, in the 3D film, released on May 18.

Depp said: ''I've worked with her twice now, and it's always been a real pleasure.

''She's very special, very talented, and also at the same time as an actress she gives you so much that you weren't necessarily expecting, so you're up on your toes.''

He hopes to continue with the hugely-successful franchise, saying: ''There's a lot more I feel I can do with these films. There are a lot more possibilities to be mined.''

On the possibility of a fifth film, he added: ''I don't know what the situation with five will be, but I do know that we're talking about it.''

Part of the film was shot in Greenwich, south-east London, which Depp particularly enjoyed.

''It's like my second home now,'' he said.

Cruz, who recently gave birth to a son, wore a long white Givenchy dress with lace sleeves and a train for the premiere. She revealed she was so keen to work on the film that she accepted the role without having read the script.

''It was a big honour to feel invited,'' she said. ''I loved the other three (films) and I love what Johnny has created.''

She said the experience of filming an action film while pregnant was made ''very easy'' for her, adding: ''Rob (Marshall), our director who we love, is an angel, and Johnny and every single person in the crew was so protective of me, and I will never forget that.''

Producer Jerry Bruckheimer said of Cruz: "She worked very hard. She's an amazing actress. We're so proud of her that she did this while she was pregnant."

Ian McShane, who plays Blackbeard in the film, said it was "nice to be home again" in the UK for some of the filming.

"We had a great time," the Lovejoy actor said. "It's a great way to spend six months of your life. It was nice to get offered a job! It's always nice."

Up-and-coming British actor Sam Claflin said the premiere had left him feeling emotional.

"To think that I'm here in my hometown, celebrating with my family and friends, I'm so privileged," he said. "I got really tearful earlier. It's just the most amazing day. I'm very happy."

The other cast members were very welcoming, he said, adding: "These are people I've grown up watching on TV and suddenly I'm rubbing shoulders with some of the world's best."

King's Speech star Geoffrey Rush said he had enjoyed making his fourth Pirates film and hoped there were many more to come.

Rush, who plays Barbossa in the series, said: "The fact that the writers keep giving me all of these new transformational qualities, it just provides new stuff to play with, and I can discover just how evil or sometimes how idiotic he can be."

It was the first Pirates Of The Caribbean film for Rob Marshall, who described Depp as "exquisite".

"We were ready for a whole new beginning and it's a really exciting cast," he said. "Everything is very fresh about it. There's a real clear narrative to the film. It's just a fun, exciting adventure. Making it was an adventure too."

Robbie Kay, 15, who plays the cabin boy, said filming had been an "amazing" experience - despite the fact that he was hoisted 50ft in the air for a stunt, and has a fear of heights.

He joked: "It wasn't the most pleasant thing."

The premiere was also attended by television presenters Gok Wan, Dermot O'Leary and Jameela Jamil, reality TV star Kerry Katona and The Saturdays singer Una Healy.

Nine-year-old Beatrice Delap was guest of honour, having first met Depp at her primary school.

The actor, in his Captain Jack outfit, paid a surprise visit to Meridian Primary School while filming in Greenwich after Beatrice wrote a letter asking him to rescue her from lessons.

She was given pride of place on the blue carpet and was hugged by the film stars as they arrived at the premiere.

Fans came from across the UK, many dressing as pirates. Two girls had even slept just outside the Westfield car park in sleeping bags last night, just so they could be at the front of the queue to meet Depp.