Exiled Cambodian Prince Norodom Sirivudh, stranded in the territory for a second night, has moved hotels and had his security tightened amid official fears for his safety. The Security Branch said it had 'legitimate concerns' for his safety. Officers from the VIP Protection Unit have been assigned to protect the prince after his second attempt to fly to Phnom Penh was thwarted amid fears of violence on his arrival in Cambodia. His political opponents - most notably Hun Sen, the co-premier the prince was convicted of plotting to kill in 1995 - have warned they were 'ready to attack with rocket launchers' any aircraft attempting to take him into Cambodia. A Security Branch spokesman said: 'We have provided security. It has not been granted on a courtesy basis because he is a prince of Cambodia, but because of legitimate security concerns.' She would not comment on whether the moves were the result of a direct threat against Prince Sirivudh. Three VIP unit officers stationed outside the prince's room at the Regal Airport Hotel turned away visitors yesterday morning and the prince later moved to another Kowloon hotel. Prince Sirivudh, who was prevented from boarding a Dragonair flight to Cambodia on Tuesday, has been granted a short-stay visa. Cambodia's national carrier, Royal Air Cambodge, yesterday sold him a ticket on today's flight to Phnom Penh but then told him he would not be allowed to board. Royal Air Cambodge chairman Vichit Ith said: 'We have given firm instructions to decline any boarding by His Highness Prince Sirivudh.' He said the decision was taken out of consideration for the safety of other passengers. Last night Tanaka Khloth, an adviser to the prince, vowed the prince would return to Cambodia 'even if it meant taking a boat'. 'We do not understand how they can give him a ticket and then refuse to let him board. He [the prince] said before he left Paris that he would take a boat if necessary. His express wish is to go to Cambodia.' Asked about security, he said: 'We want a ticket, then we will worry about that.'