A government spokesman said on Tuesday that 378 people had died and 755 were injured in a stampede on a crowded bridge.
Council of Ministers spokesman Phay Siphan said the latest figures were accurate as of late Tuesday, but would not speculate on whether he expected the death toll to rise further.
Also late Tuesday, hundreds of Buddhist monks held a ceremony at the disaster site.
They chanted prayers for those who died late Monday when a crowd of thousands panicked while crossing a 100-metre-long bridge connecting an entertainment area on Diamond Island to the mainland of Phnom Penh.
Earlier Minister of Information Khieu Kanharith said that on Thursday would be a day of remembrance for the victims, whose bodies would be transported to their homes across the country.
"The government will organise the means of transport, because in Cambodian tradition many car owners refuse to transport bodies. So we will use military trucks instead," he said.
Khieu Kanharith stressed that, contrary to earlier media reports, none of those who died had been electrocuted.
"The causes of death were firstly asphyxiation and, secondly, internal bleeding," he said. "(As of Tuesday morning) one quarter of the injured have left the hospitals."
Prime Minister Hun Sen said it was the worst death toll in such a short period since the Khmer Rouge regime was overthrown in 1979.
The stampede happened around 9:30 p.m. (1430 GMT) Monday, the final day of the annual Water Festival, an event that authorities last week predicted would attract up to 4 million people to the capital.
Khieu Kanharith said the government had established three committees to deal with the crisis: the first to investigate what had happened; the second to determine the identities of the victims; and the third to find out the cause of death of each person.
He said the government would give $1,250 to the families of each the deceased, and $250 to those who were injured.
Emergency service crews battled into early Tuesday through thick crowds to take the dead and injured to eight hospitals around the capital.
An unknown number of people jumped off the bridge to avoid the crush, and rescue crews continued to search for them during the day. Authorities in Vietnam confirmed one Vietnamese national died in the crush and another was injured.
Ly Vuthy, a vendor who witnessed the incident from her position on the island, told DPA that well over 1,000 people were on the bridge trying to leave Diamond Island when several of them fainted.
The crowd then panicked, she said, and people were packed so tightly on the bridge they were unable to move off.
"People were feeling trapped and claustrophobic, and many jumped off the bridge," she said.
Her account was backed up by Sem Pagnaseth, a vendor on the mainland side of the bridge, who said the bridge was "extremely crowded - thousands of people were on it, standing side by side like fingers pushed together."
He said barriers set up to prevent people exiting the bridge onto a road on the mainland meant that those leaving the bridge were unable to move away quickly, and the rest backed up behind them.
Sem Pagnaseth said there were few police doing crowd control before the incident, but added that quick action by the police prevented an even worse tragedy.
The dead and injured were ferried to hospitals in ambulances, pickups and private cars.
The Water Festival is an annual celebration of the end of the monsoon season. The three-day event is characterised by races along Phnom Penh's Tonle Sap river in long canoes paddled by up to 70 people.