The army "will have to use force" to reclaim Kosovo "if the international community refuses to implement what has been agreed", according to Colonel General Radovan Lazarevic, commander of the Yugoslav Army's Pristina Corps.

The warning by the general, reportedly made in an interview with the Belgrade-based weekly newspaper Nedeljni Telegraf, came as two more Serbs were killed in the province.

Paul Wood: "Nato is concerned that Belgrade has been secretly infiltrating some of Serbia's feared paramilitaries into Kosovo"

According to General Lazarevic, the Federal Republic of Yugoslavia has the right and responsibility to defend its territory and people if the UN fails to respect its decisions and the Military-Technical Agreement signed by Nato and Serbia.

"If we do not return to Kosovo-Metohija in line with the agreement, then our state will have to find other ways," he warned.

He added that the units of the Pristina Corps were massed near the border with Kosovo and that they "are working on their combat readiness".

"It is only waiting for orders to do so," he said.

Of Kosovo's pre-war Serb population of 200,000, only 30,000 have remained in the province.

Killings

Tensions in the province have been heightened in recent days, in the run-up to the demilitarisation of the Kosovo Liberation Army, scheduled for 19 September.

Two Serbs were killed by mortar fire in Donja Budriga, eastern Kosovo on Tuesday night.

The two died when as many as ten mortar rounds were fired at their village near the town of Gniljane.

The BBC's Paul Wood says that this is the latest of a number of attacks in the American-controlled part of the province.

The explosions occurred a day after Russian peacekeepers patrolling the American sector shot dead three Serbs while trying to stop them attacking ethnic Albanians.

'Nato failure'

Russia has stepped up its criticism of Nato's ability to protect the Serb population in Kosovo and the pace of disarming the Kosovo Liberation Army (KLA).

In a statement on Tuesday, Colonel General Leonid Ivashov accused Nato of failing "to ensure the security of people of different nationalities residing in the territory, primarily non-Albanians."

It was reported on Tuesday that Nato officials had agreed with leaders of the KLA on broad outlines to replace the force with an armed civilian body.

In a separate development, our correspondent says that Nato officers are increasingly concerned that Belgrade is secretly infiltrating some of Serbia's most feared paramilitary groups into Kosovo.