An elderly man talks with a policeman near the checkpoint in Kumanovo, Macedonia. May 10, 2015. [Photo/Agencies]

KUMANOVO, Macedonia - Eight police officers and 14 members of an "armed group" were killed in a day-long gun battle in an ethnic Albanian suburb of northern Macedonia, the government said on Sunday, violence that added a dangerous twist to months of political crisis.

Sporadic gunfire on Sunday, more than 24 hours after the police operation began, subsided by early afternoon and flat-bed trucks towed away several lightly-damaged armoured vehicles.

The suburb in Kumanovo, 40 km (25 miles) north of the capital Skopje in a region that saw heavy fighting during an ethnic Albanian insurgency in 2001, remained locked down by special police units.

Interior Ministry spokesman Ivo Kotevski told a news conference 37 police officers were also wounded. He said no civilians were reported killed.

The government declared two days of national mourning and President Gjorge Ivanov summoned a meeting of the national security council, inviting leaders of the opposition and the main ethnic Albanian parties in a gesture of unity.

The events, however, will deepen concern in the West over stability in the impoverished Balkan country, where the government is on the ropes over allegations by the main opposition, the Social Democrats, of illegal wire-tapping and widespread abuse of office.

Protesters demanding the resignation of conservative Prime Minister Nikola Gruevski clashed with police last week and the opposition is threatening to rally thousands on May 17.

Observers fear political leaders on either side may try to stoke ethnic tensions as leverage.