Celebrity pictures: Keira Knightley, Bruno Mars, Chloe Sevigny

Today's celebrity pictures include a coy Tulisa Contostavlos leaving a hotel in London, Klaxons keyboardist James Righton and Keira Knightley at the Box nightclub in Soho, and on/off couple Lewis Hamilton and Nicole Scherzinger hold hands as they leave Hakkasan in Mayfair.

Across the pond in New York, Bruno Mars shops with friends, Sarah Jessica Parker runs errands and actress Chloe Sevigny attends the premiere of HBO's new series Girls.

In Los Angeles, Orlando Bloom hops on his bike, model Miranda Kerr leaves her ballet class and Sir Richard Branson and Seth Green greet at a party to celebrate Virgin America's first flight to Philadelphia at the Hotel Palomar.