Elite Kenyan security forces on Sunday killed a man at the home of Deputy President William Ruto, ending a 20-hour siege that began with an attack in which a policeman was injured, police said.

Ruto and his family were not at the vast property in the northwest of the country during Saturday's attack, which came less than two weeks before the country votes in high-stakes elections.

Kenya's police chief Joseph Boinnet said Sunday morning that the assailant had just been shot and killed and "the situation is under control".

Further details and the motive for the attack remained unclear.

Boinnet said one assailant armed with a machete attacked and badly injured a police officer who was part of Ruto's security team, seized his gun and then entered the compound.

Police reinforcements arrived and the attacker fled into a building under construction near the entrance gate.

But several security sources told AFP on Saturday that the assault was staged by several people using guns.

"There are armed people who staged the attack and have shot the GSU officer and stolen his gun," one security official said, referring to the elite police General Security Unit deployed to guard Ruto's house.

- Tensions mounting ahead of vote -

Ruto had left the house shortly before the attack to attend rallies alongside President Uhuru Kenyatta, his running mate who faces a tight re-election contest on August 8 against longtime opposition leader Raila Odinga.

The attack occurred despite the round-the-clock presence of GSU guards at the property, near the town of Eldoret, some 300 kilometres (200 miles) northwest of the capital Nairobi.

The Daily Nation newspaper Sunday said "questions remained on how such a daring attack could be allowed to happen" on one of the best protected residences in the country.

Ruto's home sits in Kenya's western Rift Valley area, the flashpoint for an outbreak of election violence after the disputed 2007 polls that killed 1,100 people and tarnished Kenya's image as a regional beacon of safety and stability.

According to opinion polls, this year's election will be close and tensions have been rising.

Odinga has repeatedly claimed the government is scheming to steal the election, while Kenyatta has accused Odinga of trying to delay the polls.

Earlier this month, Human Rights Watch said it had received reports of threats and voter intimidation in Naivasha, a flashpoint town in 2007 and one of the potential hotspots in this year's election.

In the Rift Valley, hate speech flyers have been circulating and some local residents have already left their homes.

The 2007 bloodshed haunted both Ruto and Kenyatta long after it ended, when the International Criminal Court put both on trial for orchestrating the violence.

Those charges were later dropped, with ICC chief prosecutor Fatou Bensouda blaming a relentless campaign of victim intimidation for making a trial impossible.

Source: AFP