NATO and the European Union have called for a return to calm in Macedonia after clashes between police and an armed group left at least 22 people dead.

As Macedonia declared two days of mourning on Sunday, both organisations warned of the danger of escalating violence in a part of the country hit by an ethnic Albanian insurgency in 2001.

"I urge everyone to exercise restraint and avoid any further escalation, in the interest of the country and the whole region," Jens Stoltenberg, NATO secretary-general, said in a statement.

And in a statement late on Saturday, Johannes Hahn, EU enlargement commissioner, said: "Any further escalation must be avoided, not the least in the interest of the overall stability in the country." 

Ethnic Albanians make up around one quarter of Macedonia's 2.1 million population.

The Macedonian government said eight police and 14 members of an "armed group" were killed after police staged a raid in the northern town of Kumanovo, seeking armed men from Kosovo it claimed were planning to attack civilian and state targets.

Another 37 officers were wounded in Saturday's pre-dawn raid.

Ivo Kotevski, an interior ministry spokesman, said the attackers were led by ethnic Albanian former rebel commanders from Kosovo, which broke away from Serbia in war in 1999.

Kotevski named five leaders of the group, all citizens of Kosovo, as founders of paramilitary cells.

Arsenal of weapons

Kotevski said the group entered Macedonia at the beginning of May to launch attacks on state institutions and hid out in Kumanovo's western neighbourhood, where police found an arsenal of weapons.

Kumanovo is an ethnically mixed town located about 40km northeast of the capital Skopje, near the border with Kosovo and Serbia.

Saturday's incident came a day after thousands of opposition supporters joined nationwide protests against alleged police brutality.

Kotevski said no civilians were reported killed in the raid, which continued into Sunday. Many had fled, carrying their belongings in bags.

More than 30 people were arrested and some of them were taken before a judge in the capital, Skopje.

Some residents in Kumanovo were deeply sceptical of the official version of events, but Kotevski said some of the attackers killed wore uniforms with insignia of the disbanded ethnic Albanian Kosovo Liberation Army, or UCK.

Authorities said about a fortnight ago, a group of about 40 people wearing UCK uniforms attacked a police watchtower in Gosince, on Macedonia's northern border with Kosovo, and briefly captured four Macedonian police officers.

Authorities described that incident as "very serious" and said Macedonia was the "target of a terrorist attack".

Source: Agencies