Macedonian police have announced that they arrested 20 radical Muslims suspected of being members of a terrorist group that has been linked to the murder of five fishermen in early April.

Interior Minister Gordana Jankuloska said Tuesday the men were arrested in raids near the capital, Skopje, early Tuesday and have been charged with terrorism. She said the 20 detainees have fought against NATO forces in Afghanistan and Pakistan.

The five fishermen, all ethnic Macedonians, were found shot execution-style north of Skopje on April 13.

The murders have raised fears of renewed tensions between Macedonians and minority ethnic Albanians, after a spate of ethnic attacks in March.

Tensions between the two groups have been high since they fought a civil war in 2001. The violence ended with intervention by NATO.

Ethnic Albanians make up about a quarter of Macedonia's population.