Thousands of ethnic Albanians reportedly fled a northern Macedonian town because of fears of bloodshed.
More than 2,000 residents left Vaksinci, 12 miles northeast of the capital, it was reported. Residents reportedly said they were "evacuating" their homes for fear of violence. Some told journalists they spotted armed men near by.
Government officials blamed extremists and criminals for the rise in ethnic tensions.
The area is part of Macedonia's volatile north, where a six-month conflict between Macedonian government troops and ethnic Albanian militants seeking more rights in 2001 claimed hundreds of lives.
This week, hand grenades were hurled at a government building, a district court and army barracks in downtown Skopje, the capital. No one was injured in the blasts.
Also this week, police began a hunt for an ethnic Albanian suspected of briefly kidnapping two Macedonians, one of them a police officer. The suspect, identified as Avdil Jakupi, remains at large.
He is believed to belong to the self-styled Albanian National Army, a group advocating independence for Albanians living in Macedonia and elsewhere in the Balkans.