ROSTOV-ON-DON, September 15 (RIA Novosti) - Law enforcement officers have killed three militants in Nazran, the largest city in the Russian North Caucasus republic of Ingushetia, police said Tuesday.

"At about 23:40 Moscow time, unknown men in a black Lada Priora car, whom law enforcement officers tried to detain, opened fire. Three were killed by return fire," a police spokesman said, adding that a fourth militant managed to escape but was probably wounded.

The spokesman said one of those killed wore a "shakhid belt," and that weapons and ammunition were discovered inside the car.

Ingushetia and other North Caucasus republics, such as Chechnya and Dagestan, have seen an upsurge of militant violence of late, with frequent attacks on police.

The Kremlin officially ended its anti-terrorism operation in Chechnya in April. The republic saw two brutal separatist wars in the 1990s and early 2000s.