A stampede in the Cambodian capital has left at least 180 people dead after panic erupted at a water festival crammed with millions of revellers.
Dozens of ambulances with their sirens blaring raced to the scene of the tragedy, which occurred late Monday on a bridge leading to an island in Phnom Penh where festivities were being held to mark the end of the three-day annual event.
"At least 180 people died in the incident and the toll will increase," Prime Minister Hun Sen said on Cambodian television.
He added that it was not immediately clear exactly what triggered the stampede.
"This needs to be investigated more," Hun Sen said, adding that a committee would be set up to examine the incident.
He also offered his condolences to the families of the victims.
Witnesses reported people pushing and shoving in the crowd.
"We were crossing the bridge to Diamond Island when people started pushing from the other side. There was lots of screaming and panic," 23-year-old Kruon Hay told AFP at the scene.
"People started running and were falling over each other. I fell too. I only survived because other people pulled me up. Many people jumped in the water."
Police were seen carrying away dead victims at the scene, where bodies were lined up in a row on the ground. Many of the dead appeared to be young Cambodians.
"This is the biggest tragedy we have ever seen," said Sok Sambath, governor of the capital's Daun Penh district.
Dozens of people gathered outside the city's Calmette hospital, where at least 105 people were confirmed dead, according to a police officer.
More bodies were taken to other hospitals across the city, he said.
Many festival-goers were left in tears after the tragic end to the three days of boat races, concerts and fireworks.
The annual festival, one of Cambodia's largest and most exuberant, marks the reversal of the flow between the Tonle Sap and Mekong rivers.
It is also seen as a way of giving thanks to the river for providing the country with fertile land and abundant fish.