Riot police engaged in running battles Wednesday with protesters in the opposition stronghold of Kisumu in western Kenya, as presidential aspirant Raila Odinga claimed massive poll fraud, an AFP reporter witnessed.

Police fired tear gas as several hundred protesters in the neighbourhood of Kondele -- an epicentre of violence after disputed 2007 polls -- set fire to barricades and tyres and placed rocks in the streets.

A police helicopter hovered overhead as riot police wielding shields, assault rifles and batons deployed two water trucks to put out the fires.

"If Raila is not president, we can't have peace," one protester told AFP shortly before tear gas sent the crowd running.

The protesters chanted: "No Raila, no peace", their rallying cry after both 2007 and 2013 elections which the veteran opposition leader claims were stolen from him.

In 2007 post-poll violence raged for two months, leaving 1,100 dead and 600,000 displaced.

Voting in Kenya's general elections passed without incident on Tuesday but as provisional results began ticking up on the election commission website President Uhuru Kenyatta maintained a commanding lead with about 55 percent to Odinga's 44 percent.

Early Wednesday Odinga rejected the "fake" results, declaring "the system has failed".

He later detailed allegations of a massive hacking attack on the electronic tallying system, sending tensions soaring.

"Uhuru is not the elected one, he must have rigged it," said Dickson Otieno, 30 as piles of tyres burned in the street nearby.

However he said protests should be peaceful.

"The problem is between Uhuru and Raila and should not involve the common man," said Otieno.

In the early morning in Kisumu groups of mostly young men gathered on street corners, angrily discussing the results.

Steven Okeda, a 37-year-old primary school teacher, stood with others by a corrugated tin shack next to a fetid gutter in the poor, northern Kondele neighbourhood, a morning newspaper clutched in his hand.

"The voting was just okay, nothing was wrong, but the results that are going on, the transmission, that's where the problem is. What is happening here?" he asked. "Something is cooking."

"What we are saying is, Uhuru Kenyatta has stolen the election and we will not accept that," said Okeda.

Tensions also soared in Odinga's strongholds in Nairobi.

In the Mathare slum protesters placed burning barricades along a main road, while police patrolled and a helicopter flew overhead.

source: AFP