Georgian officials said five explosions struck both sides of the de-facto border between Georgia and its breakaway region of Abkhazia on Sunday, in the latest sign of growing tensions between Tbilisi and separatists.

Moscow and Tbilisi accuse each other of stirring tensions in Abkhazia, which broke away along with the region of South Ossetia from Georgian rule during wars in the 1990s. Russia provides financial support and has peacekeepers in both.

The spokesman for the Georgian-backed government-in-exile of Abkhazia accused Russia of shipping arms into Abkhazia. News agencies quoted Russia's Ministry of Defence and the Abkhazian government as denying the charge.

Georgian Interior Ministry official Shota Utiashvili said four mines exploded near the village of Rukhi in a region controlled by Georgia.

The fourth went off under a police car as officers investigated the site after the initial blasts, slightly wounding the local deputy police chief, Utiashvili told Reuters.

The fifth bomb exploded in "territory which is de facto controlled by the Abkhaz side in the village of Otobia", Utiashvili said. The site was being investigated by the United Nations mission based in the region.

Colonel Clive Trott, who was at the scene of the blast, said it looked like a mortar round.

A Russian commander in Abkhazia said the uniform of a Georgian special forces member was found wrapped around the remains of a shell that had been the source of the blasts, RIA news agency reported.

"In the place of the explosion, there remained the uniform," assistant commander Alexander Novitsky was quoted as saying.

On Saturday, Russian President Dmitry Medvedev urged Georgian President Mikheil Saakashvili to refrain from "stoking tensions" in Abkhazia and South Ossetia.

Tbilisi accuses Moscow of seeking to annex the regions, where the majority of the population hold Russian passports. Moscow denies such plans and in turn accuses Tbilisi of seeking to restore control over the provinces by force.

Georgia, which seeks membership of NATO and the European Union, has said it wants to replace Russian peacekeepers currently stationed there with an international force.

The spokesman of the Georgian-backed government-in-exile of Abkhazia, Irakly Tsanava, said Russia was violating agreements by bringing arms into Abkhazia. "These acts are extreme and aimed against the Tbilisi and the country," said Tsanava.

Georgia's Rustavi-2 reported that 45 wagonloads of arms entered the capital of Sukhumi. The arms included anti-aircraft systems, anti-aircraft radar and armoured vehicles, as well as helicopters and tanks.

Russia and Abkhazia denied the charges, news agencies said.