The government of the Former Yugoslavian Republic of Macedonia declared two days of national mourning after six special police officers were killed and 30 others wounded during a gun battle in the northern town of Kumanovo.
Six special policemen were reported dead and 20 injured in clashes with men believed to be ethnic Albanians, according to local media.
The government declared two days of national mourning after the incident.
It remains unclear what has happened to the armed group, believed to number at least 30, amid reports that most of them have surrendered.
Kumanovo is an ethnically mixed town located about 40 km northeast of the capital Skopje, near the border with Kosovo and Serbia.
The Kumanovo region saw hostilities between ethnic Albanian rebels and government forces during ethnic conflict in 2001.
The rebels were demanding greater rights for the ethnic Albanian minority.
This incident came a day after thousands of opposition supporters joined nationwide protests against alleged police brutality.