More than 18,000 refugees have gone to Kosovo since last Friday

More than 20 Macedonian soldiers have been killed in clashes with ethnic Albanian rebels fighting mainly in northern Macedonia.

Rebels are now in mortar range of Skopje's international airport.

Peace plan agreed

The resignation was announced as the Macedonian Government, which includes ethnic Albanian representatives, accepted President Boris Trajkovski's peace plan to end the four month-old conflict.

Among other things, the plan envisages an amnesty for the rebels.

Truce holds

Ceasefires declared on Monday by Macedonian forces and ethnic Albanian rebels appear to be holding, despite an overnight gun battle outside the northern city of Tetovo.

Nine police officers were wounded, two of them seriously, during the exchange which lasted until dawn. They are now said to be better.

Trajkovski: Hoping for rebel withdrawal to Kosovo

The attack came only hours after the Macedonian army announced its temporary ceasefire in its shelling of rebel-held villages in the north of the country.

Click here to see map of the region

Ethnic Albanian rebels have apologised for the attack, describing it as a "mistake".

But people have continued to flee the area to neighbouring Kosovo. The United Nations refugee agency says around 18,000 civilians have arrived in the province since Friday.

Humanitarian agencies have been using the lull in the fighting to deliver aid to thousands of ethnic Albanian civilians caught up in the conflict, and to restore the water supply to the city of Kumanovo.

The supply has been cut off since the city's reservoirs fell under rebel control last week.

About 1,000 rebels, who have been in control of the village of Aracinovo - less than 10km (6 miles) from Skopje - since last Friday had given the government until 0200 GMT on Monday to stop its attacks in northern Macedonia or face a retaliation on the capital.

Peace plan

President Trajkovski's three-part plan addresses the key issues of rebel disarmament, political reform to calm ethnic tensions and overhauling the armed forces.

The proposal also contemplates an amnesty for fighters, but, as Mr Trajkovski put it last week "terrorist leaders of today and tomorrow will be eliminated unless they go back where they came from".

Defence Minister Vlado Buckovski said a civil committee of cabinet ministers and defence experts would be set up to tackle the crisis, and that it would oversee a new anti-terrorist force of special police and elite troops.