Haiti's government has accused foreign aid donors for fuelling political unrest as opposition groups plan a mass demonstration for Friday.

Donors, led by the US, have frozen about $500m to the poverty-stricken Caribbean island because of a dispute over the integrity of parliamentary elections in 2000.

"If aid to the country would be unblocked, every Haitian will benefit," said President Jean-Bertrand Aristide during a reception for visiting South African Foreign Minister Nkosazana Dlamini Zuma.

"The opposition has a responsibility to help unblock the country and unfreeze the money," he said.

The poorest country in the Americas has been rocked by violent anti-government protests led by students, trade unions and opposition politicians who have called for Mr Aristide to resign.

The opposition Democratic Convergence accuse the former Catholic priest of corruption, political repression and rigging elections in 2000 that his Lavalas Family party won.

Protest violence

Anti-government protestors plan to march on the National Palace in the capital on Friday.

Mr Aristide has refused to step down, accusing the opposition of planning a coup to overthrow him before the end of his five-year term in 2006.

A protest on Wednesday claimed the fourth life since mid-November when a pedestrian was shot in the head as riot police clashed with anti-government demonstrators.

Most Haitian cities were brought to a standstill on Tuesday by a strike by transport workers over fuel price rises.

The International Monetary Fund has demanded fuel subsidies be cut before the disbursement of a $50m loan, part of the $500m being withheld.

The government has called for new elections, which was rejected by the opposition who blamed security concerns.

Mr Aristide was first elected as president in 1990 but was ousted in a coup months later.

An influx of refugees to the US prompted it to invade in 1994 and restore him to power.