pbr Cambodian Prime Minister Hun Sen paid his respects on Thursday during a day of national mourning to honour the more than 350 people who were killed in a deadly stampede in Phnom Penh.br ppbr Accompanied by his wife and government officials, Hun Sen placed incense sticks by a wreath at the site of Monday's stampede.br ppbr The tragedy unfolded after crowds celebrating a water festival flocked to an island for a free concert and spilled onto a bridge to the mainland.br ppbr An estimated seven to eight thousand people were streaming over the bridge that connects the island to the mainland when it began to sway, according to local reports.br ppbr According to an investigation, the swaying of the bridge loaded with thousands of people sparked the mass panic.br ppbr An official report, however, has not yet been released.br ppbr Information Minister Khieu Kanharith said on Wednesday the official death toll was 351 dead with 395 injured.br ppbr Premier Hun Sen described the stampede as the biggest tragedy since the communist Khmer Rouge's reign of terror, which killed an estimated 1.7 million people in the late 1970s.