Nationalist protesters had to be forced back with tear gas in clashes that left about 30 police and rioters injured, a government spokesman said.

They were angry at concessions to the ethnic Albanian minority.

Minister Vlado Buckovski and a party colleague were trapped for several hours inside their party's headquarters in the south-western town of Struga.

Western pressure

Mr Buckovski and the general secretary of the Social Democrat Party were taken away unharmed, a police source said.

But the violence spread across the town.

The revolt was in response to an agreement to restructure local government and to allow greater Albanian language rights.

The moves follow Western pressure to give ethnic Albanian areas more autonomy.

A decision last week by Macedonia's coalition government means municipal boundaries can be redrawn.

Struga has seen several protests in the past week

In areas like Struga, that means Albanian political leaders could be given control over schools, health and local economic development.

Opposition parties say the proposals will divide the country along ethnic lines. More protests are scheduled for Monday, when the measures will be debated in parliament.

A quarter of Macedonia's two million people are ethnic Albanian.