Thousands of people gathered in Phnom Penh Monday to begin three days of independence celebrations, 56 years after Cambodia left 90 years of French colonial rule.

King Norodom Sihamoni, whose father, Norodom Sihanouk, led the country through independence, lighted the flame of victory at Independence Monument, which will burn for three days to honor “patriots” who died in the cause of national independence.

Senior government officials, including Prime Minister Hun Sen, attended the ceremony, as well as students and foreign diplomats attended the ceremony.

“This Nov. 9 Independence Day is a day to bring happiness and prosperity to Cambodians,” Kem Sokha, president of the Human Rights Party, said in a letter to the king, calling it a day for “mass solidarity under the shade of the royal crown.”

However, the day of celebration was darkened by a lingering diplomatic row with neighboring Thailand over the appointment of ousted Thai premier Thaksin Shinawatra as an economic adviser to Hun Sen.

Hun Sen said on Sunday Thaksin could travel to Cambodia this week, to give a lecture to Cambodian officials, a move opposed by Bangkok, which withdrew its ambassador last week.

Thai Deputy Prime Minister Suthep Thaugsuban said Monday Thailand would officially contact Cambodia over extradition if Thaksin arrives in Cambodia.

Cambodia has also withdrawn its ambassador from Bangkok. Thai officials say the next step could be to close the borders.