As he stood on a highway overpass watching riot police play a cat-and-mouse game with stick-wielding protesters in the streets of the Kenyan city Kisumu, Dickson Otieno thought to himself "not again".

Ten years ago, the city was wracked with violence after a disputed presidential vote, and there were fears it might happen again on Wednesday, not 24 hours after Kenyans voted in a general election.

"They should not do that," Otieno said of the rioters in the streets below him as they burned tyres and chanted slogans.

Despite a massive security deployment and calls for peace by Kenya's main politicians, unrest has broken out in some parts of Kenya after leading opposition politician Raila Odinga alleged that the electoral commission (IEBC) has been penetrated by computer hackers who rigged the vote against him.

Odinga is behind in the IEBC's preliminary results based on 14.6 million ballots counted, which show President Uhuru Kenyatta well on his way to winning a second term in office with 54.7 percent of the vote to Odinga's 44.8 percent.

As the sun rose on Wednesday, Odinga supporters in Kisumu, a stronghold of his on the shores of Lake Victoria, stood in angry knots on street corners, puzzling over the news.

"Something is cooking," said Steven Okeda, a 37-year-old primary school teacher. "What we are saying is, Uhuru Kenyatta has stolen the election and we will not accept that."

By late morning, the tension had boiled over in Kisumu's poor Kondele neighbourhood, and in some parts of the capital Nairobi.

Both areas were scenes of terrible violence after a disputed presidential vote in 2007 that degenerated into two months of politically motivated ethnic bloodshed and left 1,100 people dead and 600,000 displaced.

And in both cities on Wednesday, protesters chanted "No Raila, no peace", their rallying cry after the 2007 and 2013 elections which Odinga claims were stolen from him.

In Kisumu, a police helicopter hovered overhead as officers engaged in running battles with protesters, who would disperse as officers advanced, only to then re-emerge and re-group minutes later.

"If Raila is not president, we can't have peace," one protester told AFP shortly before tear gas again sent the crowd running. Later in the day police fired rubber bullets.

- 'Why are you doing this?'-

The violence was more severe in Mathare, a slum in Nairobi.

Police there said two protesters were killed.

Japheth Koome, police chief for Nairobi, said the two who were killed had tried to "attack our officers with pangas (machetes) and that's when the officers opened fire on them."

An AFP reporter saw the body of a young man who appeared to have been shot in the head lying in a narrow alley.

"You're Kenyans, why are you doing this?" protesters shouted at officers they blamed for the death as the man's mother stood nearby with her hands on her head, wailing.

All the unrest strikes Otieno as pointless. While he believes Odinga has been cheated, he sees no reason why the consequences of that should be borne by Kenyans.

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

Source: AFP