Hun Sen hospitalised in Singapore
Facebook/Hun Sen

Cambodian Prime Minister Hun Sen has been admitted in a hospital in Singapore, he said on his Facebook page on Thursday. He is one of the world's longest serving rulers after more than three decades in power.

The 64-year-old minister had fallen ill because he was very tired and needed urgent medical treatment. In his post, he said that he had been in hospital since Wednesday, but planned to return to Cambodia on May 7 to resume work as normal.

Several pictures that were posted on his social media account showed Hun Sen in bed with family members at his side. Last year, he was briefly hospitalised in Singapore.

The former Khmer Rouge guerrilla has ruled his South-east Asian country with an iron hand since 1985, a period in which Cambodia has emerged from the aftermath of genocide to become one of the region's fastest growing economies.

Hun Sen and his allies have been accused of promoting corruption and human rights abuses. The opponents also accused him of using unfair measures to undermine rivals in the run-up to local elections next month and a general election next year.

On Thursday, the European Union called on the government to respect the rights of five human rights workers, who were detained for more than a year without trial in a political case. Last week, a court extended their detention for a further six months.