Two gunmen from Ukraine's notorious nationalist militia Right Sector have briefly taken a six-year-old boy hostage in western Ukraine as a standoff between the gunmen and police entered its third day.

Two people were killed Saturday in a Right Sector gun-and-grenade attack on police in a western Ukrainian city. Police had surrounded some gunmen in a wooded area of the city of Mukacheve and have been trying to negotiate their surrender since then.

The Ukrainian Interior Ministry said in a statement Monday that police and security services had tracked two Right Sector gunmen outside Mukacheve but they took a six-year-old boy hostage and managed to escape.

Right Sector said its members were trying to confront policemen who they said were involved in contraband in the region.