A preliminary investigation into a stampede that left 456 people dead in Cambodia on Monday has found that the swaying of a suspension footbridge triggered the panic.
The disaster occurred as huge crowd used the bridge to get to an island near the capital Phnom Penh where an annual water festival was being held on Monday.
The BBC reports some people were crushed on the bridge and many others fell into the water and drowned.
According to a TV station, the inquiry found that many on the suspension bridge were from the countryside and were unaware such structures often swayed in the wind or when large numbers of people used them.
Prime Minister Hun Sen has declared Thursday a day of national mourning.
He said the stampede was the country's biggest tragedy since the Khmer Rouge era in the 1970s, which left an estimated 1.7 million people dead.
Officials initially said 378 people were killed and 755 injured, but Social Affairs Minister Ith Samheng said on Wednesday that the official death toll was now 456.
The BBC reports the stampede is the world's worst since 2005, when more than 1000 Shia pilgrims were crushed to death or drowned in the Tigris river in Baghdad, Iraq, after rumours of a suicide bomb attack sparked a panic.