By Ognen Teofilovski
KUMANOVO, Macedonia (Reuters) - Heavily armed police entered the outskirts of a north Macedonian town on Saturday in what a spokesman described as an operation against an "armed group", heightening fears of instability in the ex-Yugoslav republic after months of political crisis.
A Reuters photographer said special police units in armored vehicles had locked down a suburb of Kumanovo, some 40 km (25 miles) north of the capital Skopje, and local media reported the sound of automatic gunfire in the early morning.
Helicopters flew overhead in a region that saw fighting between government forces and ethnic Albanian guerrillas in 2001 before Western diplomacy averted an all-out civil war.
A hospital source, who declined to be named, told Reuters that at least three officers had been seriously wounded.
A spokesman for the Interior Ministry said only that police had launched an operation "on previously received information about an armed group", without elaborating.
The events are likely to deepen concern in the West over stability in Macedonia, where the government is on the ropes over opposition allegations of illegal wire-tapping and widespread abuse of office.
The opposition has begun small but daily protests demanding the resignation of conservative Prime Minister Nikola Gruevski, and is threatening to rally thousands on May 17.
Observers fear political leaders on either side may try to stir ethnic tensions as leverage.
An estimated 30 percent of Macedonia's 2 million people are ethnic Albanians. Guerrillas took up arms in 2001, clashing with security forces before the West brokered a peace deal offering the Albanian minority greater rights and representation and the insurgents entered politics.
But implementation has been slow and tensions sometimes flare. Many in Macedonia, regardless of ethnicity, are frustrated at the glacial pace of development and integration with the West, with the country's bid to join the European Union and NATO blocked by a long-running dispute with Greece over the country's name.
(Additional reporting by Kole Casule in SKOPJE; Writing by Matt Robinson; Editing by Louise Ireland)