Kumanovo, Macedonia — An armed group battling Macedonian police over the weekend aimed to destabilize the country by attacking state buildings and public areas, the prime minister said Sunday. The attacks left at least 22 people dead, a top official said.

Interior Ministry spokesman Ivo Kotevski, who gave the death toll, called the attackers in the northern town of Kumanovo "terrorists." He said police were still searching for other bodies but did not believe anyone from the armed group was still at large.

The 40 plus-strong group was targeting state institutions, sports events and shopping malls and was made up of well-trained fighters who had participated in attacks in the region and the Middle East, Prime Minister Nikola Gruevski told reporters in the capital of Skopje.

"One of the aims of the group, at least, was to destabilize Macedonia," Gruevski added.

The fighting comes as Macedonia is grappling with its deepest political crisis since its independence from the former Yugoslavia in 1991. The government and the opposition have accused each other of planning to destabilize the country to take or preserve power, and some analysts fear leaders on both sides are ready to provoke ethnic clashes.

Gruevski effusively praised the police, among whom 8 died and 37 were injured. At least 14 alleged members of the armed group were also killed.

"Macedonian police have performed the most complicated operation and the police forces, with officers from all ethnic groups, have performed a professional, heroic and patriotic operation", Gruevski said at a press conference.

He added that the armed group was not supported by members of Macedonia's ethnic Albanian minority.

Kotevski said some of dead attackers wore uniforms with the insignia of the disbanded ethnic Albanian Kosovo Liberation Army, or UCK. No identification documents were found on them. The UCK, an ethnic Albanian rebel group, fought Serb government forces in 1998-99 for the independence of neighboring Kosovo.

Kotevski named five leaders of the group, all citizens of Kosovo, as founders of paramilitary cells. He said the group entered Macedonia at the beginning of May to launch attacks on state institutions and hid out in Kumanovo's western neighborhood, where police found a huge arsenal of weapons.

Police have filed terrorism-related charges against more than 30 members of the group that have surrendered. Later Sunday, they are expected to be brought before an investigative judge.

Kumanovo is an ethnically mixed town 25 miles northeast of Skopje, near the border with Kosovo and Serbia. The region was the center of hostilities between ethnic Albanian rebels and government forces during the ethnic conflict in 2001. That insurgency ended after six months with a Western-brokered peace deal that granted more rights to ethnic Albanians, who make up about a quarter of the country's 2 million people.

About two weeks ago, authorities said the group of 40 wearing UCK uniforms attacked a police watchtower in Gosince on Macedonia's northern border with Kosovo and briefly captured four Macedonian police officers.

On Sunday, the Macedonian government declared two days of mourning for those killed in the clashes and President Gjorge Ivanov called for a National Security Council meeting. National flags were flying at half-mast and sports events and political gatherings were canceled.

EU Enlargement Commissioner Johannes Hahn expressed "deep concern" at the situation around Kumanovo.

"Any further escalation must be avoided, not the least in the interest of the overall stability in the country," Hahn said.

Observers from the Organization for Security and Cooperation in Europe (OSCE) were in Kumanovo to tour the site of the armed clashes.