Kyrgyzstan's interim government said on Monday it had arrested a "well-known person" on suspicion of fomenting the worst ethnic riots in 20 years, which have killed at least 117 and left cities in flames.

The Interior Ministry in the Central Asian state, which hosts Russian and US military bases, said the situation in Osh and Jalalabad was "tense". A witness in Osh said gangs resumed shooting on Monday at residents and homes in one area of the city.

The interim government said authorities in Jalalabad had made an arrest. It did not disclose the person's identity, but repeated accusations that supporters of ex-president Kurmanbek Bakiyev, who was overthrown in April, were behind the violence.

Bakiyev, in exile in Belarus, issued a statement from there on Sunday in which he denied claims he was behind the clashes.

But Kubatbek Baibolov, commandant in Jalalabad, said in televised comments: "This is nothing other than an attempt by Bakiyev's supporters and relatives to seize power."

The ethnic violence between Kyrgyz and Uzbek residents began late on Thursday and escalated over the weekend. Witnesses said gangs armed with automatic rifles, iron bars and machetes had set fire to houses and shot fleeing residents.