Rival ethnic groups in Kenya who fought after the 2007 election are rearming in readiness for violence at the 2012 poll, a BBC investigation has found.
It is feared villagers in Rift Valley province are moving from traditional weapons such as spears to machine guns.
Government officials insist they are tackling the influx of illegal arms.
But they have been widely criticised for failing to punish the ringleaders of violence after the 2007 election, in which 1,300 people died.
A power-sharing government was formed in early 2008 to quell the violence.
It has been under international pressure to investigate the killings ever since, but its failure to organise a local tribunal has forced the International Criminal Court to step in to prosecute suspects.
Ethnic arms race
The BBC's Network Africa programme discovered arms dealers selling sophisticated weaponry in the Rift Valley - an area hard-hit by ethnic violence in early 2008.
Compared to guns, the arrows were child's play
Kalenjin man
One arms dealer told the programme supply was high and prices were low at the moment.
"Right now we have AK47 rifles for sale but there are times when we also sell G3s [rifles]," he said.
"In a month we sell more than 100 rifles."
Members of the Kalenjin community and their rivals, the Kikuyu - the country's dominant ethnic group - both said they were arming to protect themselves.
"We bought the guns because we hear the Kikuyu have also bought guns," said a Kalenjin man who declined to be named.
"Before we were using bows and arrows to fight the enemy but changed to guns following the post-election experience because we realised, compared to guns, the arrows were child's play."
A member of the Kikuyu community said he was not willing to "wait until 2012 to be killed".
"We have to arm ourselves. I did not acquire this gun to commit offences," he said.
'Time-bomb'
For weeks after the 2007 election the two communities fought in bloody clashes.
The Kalenjins were convinced their candidate, Raila Odinga, had been cheated of victory by President Mwai Kibaki, a Kikuyu.
After weeks of bloodshed, the two men formed a power-sharing government with the president keeping his job and Mr Odinga being brought in as prime minister.
But the UN has warned that a similar flare-up could occur after the 2012 vote unless Kenya strengthens its institutions and the perpetrators of the 2007 violence are punished.
Kipkorir Ngetich, of the Eldoret human rights group expressed similar fears and said his research backed the BBC's findings - that the communities are rearming.
"We are appealing to the government to investigate the matter because it is a time-bomb that will soon explode," he said.
Kenya's deputy minister for internal security, Orwa Ojode, said he was aware of the problem and had ordered the police to clamp down on the sales.
"We will definitely apprehend those who are behind the sale of illegal arms," he said.
He blamed the country's porous borders and its proximity to unstable states like Somalia for the influx of guns.