Haiti's president has appealed for calm amid fears that riots aimed at UN peacekeepers over a cholera epidemic could spread to the capital, saying the violence has hurt efforts to fight the disease.
In a national address after health officials announced that the death toll from cholera had risen above 1,000, President Rene Preval said barricades were keeping people from getting needed care and warned protesters that looting would not help stem the epidemic.
The UN cancelled flights carrying three metric tonnes of soap along with other medical supplies and personnel to Cap-Haitien because of violence in Haiti's north, the UN Office for the Coordination of Humanitarian Affairs said. Flights were also cancelled to Port-de-Paix.
Oxfam suspended water chlorination projects and the World Health Organisation halted training of medical staff, the UN humanitarian office said. A UN World Food Programme warehouse was looted and burned.
The capital, Port-au-Prince, was calm on Tuesday but there were worries that protests could erupt in the city, which was devastated by last January's earthquake.
The Haitian government sent top officials to the north on Tuesday in the hope of quelling the unrest. Haiti's police chief, the health minister and other Cabinet officials headed to Cap-Haitien, the country's second largest city, where protesters erected barricades of flaming tires and other debris and clashed with UN troops.
At least two demonstrators have died, one of them shot by a member of the multinational peacekeeping force that has been trying to keep order since 2004.
During a second day of rioting, local reporters said a police station was burned in Cap-Haitien and rocks were thrown at peacekeeping bases.
UN peacekeepers found themselves in the difficult job of quelling unrest aimed at them. The violence has combined some Haitians' long-standing resentment of the 12,000-member UN military mission with the internationally shared suspicion that a UN base could have been a source of the infection.
UN officials deny responsibility. The group said the protests were politically motivated to affect or disrupt national elections scheduled for November 28.