Haitians run through the streets during protests against the rising cost of living
Haiti's President Rene Preval has ordered people to stop rioting over soaring food and fuel prices.
"To those who are stirring up violence, I order you to stop because it is not going to solve the problem," Mr Preval said on national TV and radio.
Five people have died in a week of rioting in Haiti, a rice importer and one of the world's poorest countries.
On Wednesday, barricades of burning tyres spewed out black smoke above the capital and gunshots rang out.
Bands of young men carrying sticks, rocks, and guns looted stores and roamed streets deserted of cars in Port-au-Prince.
Local media also reported protests elsewhere, including Grand-Goave to the south of the capital, and Gonaives, Ouanaminthe, Cap-Haitien and St Marc to the north.
Meanwhile, the US said it was suspending operations at its embassy, and advised American citizens to stay indoors.
President breaks silence
In his first address since the rioting began in the southern city of Les Cayes last Wednesday, Mr Preval said he had ordered Haitian police and the 9,000 or so UN peacekeepers in the country to put a stop to the looting.
He floated the possibility of increased government subsidies on production of staple foods.
But it is unclear whether this will placate rioters who have demanded the government scrap all taxes on staples - and the president's resignation.
"You haven't seen nothing yet," Jeanti Mathieu, 22, told Reuters news agency shortly before Mr Preval's address.
"We are waiting for the government to tell us what it is going to do. Otherwise you can expect the worst," he said, as he helped erect a street barricade made of wrecked cars, concrete blocks and debris.
UN peacekeepers in the capital for a second day reportedly fired in the air and used tear gas to prevent demonstrators trying to get into the presidential palace where Mr Preval is believed to be staying.
The UN General Secretary Ban Ki-moon "appealed for calm and urged demonstrators to refrain from further acts of violence", his press office said in a statement.
In recent months, it has become common among Haiti's poor to use the expression "grangou klowox" or "eating bleach", to describe the daily hunger pains people face, because of the burning feeling in their stomachs.
Global food prices have on average nearly doubled since mid-2007, with rice costs rising even more. Energy costs have also risen.
Haitians - most of whom have no more than $2 (£1) a day to live on - now say they are struggling to feed themselves.