A truck carrying gasoline has exploded in northern Haiti, killing more than 40 people and injuring dozens of others, officials and news reports said.
The blast occurred late Monday in the city of Cap-Haitien, Prime Minister Ariel Henry said, adding that he was devastated.
"Three days of national mourning will be decreed throughout the territory, in memory of the victims of this tragedy that the entire Haitian nation is grieving," he tweeted.
Mr Henry said his administration was deploying field hospitals to the area to help those affected.
No further details were immediately available. Police didn't immediately return calls requesting information.
Le Nouvelliste newspaper reported that dozens have been hospitalised with injuries and that hospitals were seeking supplies.
"We are overwhelmed," a person identified as Dr Calhil Turenne told the paper.
Dave Larose, a civil engineer who works in Cap-Haitien, told The Associated Press that he was driving when he saw ambulances and a crowd of people gathered along a road around 1am.
He said he observed how some people were using buckets to scoop up gasoline from the truck and the street to take back to their house.
The explosion occurred as Haiti struggles with a severe shortage of fuel and spiralling gas prices.
"It's terrible what our country has to go through" Larose said.
Former Prime Minister Claude Joseph also mourned the victims, tweeting, "I share the pain and sorrow of all the people."