Three people have died in an explosion in a Mombasa nightclub where football fans had gathered to watch England play Italy in the Euro 2012 championships.

The cause of the explosion is not yet known but police said they have arrested a suspect.

There have been several attacks in the east African port since Kenya sent troops into Somalia in October to crush Islamist militants.

A day before Sunday's blast the US embassy warned of an imminent attack on Mombasa and urged all its staff to leave. It also said it had suspended travel to the city by embassy staff until July 1.

Police said a man in his 20s, wounded in the blast and taken to hospital, has been arrested. He had suffered abdominal and leg injuries. A police spokesman said: "One of the wounded people is assisting us with investigations because he is providing contradictory statements. He is being held as a suspect."

At least 15 people have been killed in recent grenade attacks in Nairobi and Mombasa. Kenya blames al Shabaab, a Somali rebel group with links to al Qaeda.