Macedonian helicopters and artillery launched an assault on ethnic Albanian rebel positions close to Skopje yesterday, ending an 11-day truce.
The attack on Aracinovo and surrounding villages was one of the most intense since the conflict began four months ago. The Macedonian army used multiple rocket launchers, tanks and mortars, hitting houses on the east side of the town.
A government spokesman said the attack, launched before dawn, was a deliberate attempt to sway the negotiation process its way. Talks between parties representing the Slavic majority and the ethnic Albanian minority broke down on Wednesday.
"We need some advance on the ground in order to create better conditions for dialogue," Mr Antonio Milososki, the Prime Minister's spokesman, said.
European Union officials who had hoped for a political agreement by the beginning of next week saw the resumed fighting as a significant setback.
The EU foreign affairs chief, Mr Javier Solana, flew into Skopje on Thursday night to try to shore up the negotiations. Yesterday he was trying to reach President Boris Trajkovski by phone to discuss the situation.
"The ceasefire was important for the talks," Ms Christina Gallach, a spokeswoman in Skopje for the European commission said. "We were hoping to put the dialogue in motion before Monday's Foreign Ministers' meeting in Luxembourg, particularly when NATO has already offered troops to help implement an accord. But this is now complicated by the security situation."
The leader of the ethnic Albanian rebels in Aracinovo, who calls himself Commander Hoxha, claimed that three civilians had been killed and several wounded in the fighting yesterday: "I'm warning the government, if they want war they are going to get one," he declared.
The government countered claims that civilians had been hit by claiming that Aracinovo was occupied by gunmen only.
The Albanian MP for the area, Mr Ismet Ramadani of the Democratic Prosperity party (PDP), said he was in contact with several families in the town who said there had been "continuous bombardment". He said he had tried to ring the Prime Minister, Mr Lujbko Georgievski, to complain about the attack.