Nairobi: Police have started firing tear gas and water cannons at crowds who have gathered in the Kenyan capital to protest against the result of the presidential election.

Kenyan opposition leader Raila Odinga had called for a million people to gather in Nairobi's Uhuru Park, even though the protest had been banned.

Odinga’s supporters, many of whom are wearing white scarves, started gathering in the park from the early hours, despite police warnings of tough action.

More than 300 people have been killed in violence across the country since Mwai Kibaki was declared president on Sunday.

He won a close vote against Odinga, but the election has been dogged by allegations of vote rigging.

The violence has spilled over from political into tribal trouble, with supporters of both candidates accusing each other of genocide and ethnic cleansing.