The body of former King Norodom Sihanouk has been returned to Cambodia for a week of official mourning. A coffin carrying the former king was flown from the Chinese capital, Beijing, where he died on Monday. As many as 100,000 people are expected to line the route the coffin will take from the airport to the royal palace. Grieving Cambodians wore black ribbons and flags flew at half-mast after news broke that the 89-year-old had died of a heart attack in Beijing. In Phnom Penh, students wearing white shirts with black ribbons pinned on them sang songs before offering flowers at the royal palace. "In the king's whole life, whatever he did was for the country, not for himself. So we are here to mourn him and we consider that he is a hero and I never had this sadness in 20 years," Lay Rithiya, a law student, told Reuters news agency. Officials from the US, China, North Korea, Japan and other countries also sent messages of condolence. Early on Wednesday, the former king's coffin was driven from the Beijing hospital where he died to the airport for the flight home. The flight landed in Phnom Penh at 1500 local time (0800GMT). Sihanouk's coffin will now be driven past mourners to the royal palace. The government has ordered all radio and television stations to refrain from broadcasting any programmes that may be deemed inappropriate during the mourning period. Sihanouk's body will remain at the palace for three months for people to pay their respects before an elaborate funeral and cremation, said the government. Sihanouk became king in 1941 while still a teenager, and led Cambodia to independence from France in 1953. He was a presence through decades of political and social turmoil in Cambodia, despite long periods of exile overseas. In later life, he emerged as a peacemaker who helped bring stability back to his country, after an ill-fated choice to back the Khmer Rouge in its early years. He remained an influential figure in his country, despite his abdication in 2004 in favour of his son King Norodom Sihamoni who, along with Prime Minister Hun Sen, is accompanying his body home.