Kenyan police have fired tear gas and water cannons to disperse protesters as thousands took to the streets to mark the first anniversary of anti-government demonstrations that left dozens dead.

At least 60 people were killed in a wave of anti-government protests last year. The authorities have not yet given any casualty figures from Wednesday's protests, but the Kenya Medical Association, Law Society of Kenya and the Police Reforms Working Group said in a joint statement that at least eight protesters were killed.

Demonstrators joined antigovernment marches across the country a year after huge rallies against a contentious tax plan left more than 60 people dead.