Liberia's government has imposed a round-the-clock curfew in the capital, Monrovia, after a day of rioting.

Young people in mobs rampaged through the city earlier Friday, burning buildings and cars. U.N. peacekeepers fired warning shots to restore order.

Witnesses say one U.N. vehicle used in trying to disperse a crowd inadvertently crushed and killed three people.

The violence began as a rare dispute between Christians and Muslims - but it remains unclear what exactly sparked the riots. Many of the burned buildings were churches and mosques.

By dusk Friday, the city was mostly quiet, although sporadic gunfire could still be heard.

Liberia is struggling to recover from 14 years of nearly non-stop civil war.