United Nations reinforcements are heading to Haiti to relieve the overstretched peacekeeping force there.

First to arrive will be 125 police officers from China, expected to arrive on the Caribbean island on Sunday. Additional troops from Spain, Morocco and Sri Lanka are expected to land in Haiti later this month.

Fewer than half of the 8,000 troops authorized for peacekeeping duty in Haiti have been deployed, and the Brazilian-led force currently on the island is said to be in urgent need of reinforcements.

Gunfire erupted in Haiti's capital Friday as supporters of ousted President Jean-Bertrand Aristide marked the anniversary of his return from exile in 1994.

Mr. Aristide's supporters have been blamed for weeks of violence in Haiti. More than 20 people have died in the unrest.

The former president left Haiti after an uprising in February. Mr. Aristide said later that he did not step down voluntarily, but had been pressured to yield power by diplomats from the United States and other countries.