Gunmen shot and killed two girls today after a week of violent flare-ups in Russia's southern republic of Chechnya, Russian news agencies reported.

Hedi and Mata Saidumova, ages five and eight, died when unidentified gunmen fired grenade launchers and rifles at a convoy carrying them and their uncle, a representative of Chechnya's human rights ombudsman, a Russian news agency said.

Ombudsman Nurdi Nukhazhiev told news agency Interfax that his representative Khasambek Zubairev and two other men also riding in the cars were injured in the gunfire.

"Zubairev, having a college degree in divinity, was actively explaining and supporting the positions taken by President Ramzan Kadyrov in connection with the "Vostok" battalion situation," said Mr Nukhazhiev.

Earlier in the week, the "Vostok" battalion, a pro-Kremlin militia outside Kadyrov's command, squared off in a gunfight with soldiers loyal to the president after vehicle convoys ran into each other in Gudermes, the town where the president lives.

A witness told Reuters around 18 people died in that battle.

Russia has fought two wars against Chechen and foreign insurgents since 1994, but over the last few years has ceded local power to former enemy warlords and their fighters, isolating the dwindling number of rebel holdouts.

The Kremlin has since retrained and equipped thousands of former Chechen rebels, but tensions and rivalries between the various factions remain high.

Interfax quoted Ombudsman Nukhazhiev as saying he suspected forces from the "Vostok" battalion were behind today's shooting.

"We cannot confirm that the Vostok battalion were involved in the incident, but we have solidly-founded suspicions that they were, and consider it imperative that investigators look into this version," he told Interfax.