By Prak Chan Thul
PHNOM PENH (Reuters) - Thousands of people gathered for the funeral of prominent government critic and activist Kem Ley in Cambodia's capital on Monday, a day after he was shot dead in broad daylight inside a convenience store in Phnom Penh.
Some mourners said Kem Ley's death was a "political killing", while Prime Minister Hun Sen called for calm.
Kem Ley's killing comes amid rising political tension in the capital between Hun Sen and an opposition hoping to challenge his grip on power at local elections in 2017 and national elections in 2018.
Members of the opposition and activists have been jailed on charges they say were trumped up by the government as part of a crackdown to mute critics ahead of the vote.
Mourners burned incense and offered lotus flowers on Monday in respect to Kem Ley, 46, who was gunned down on Sunday.
His body, covered with the Cambodian flag and jasmine flowers, will be laid out for 10 days for those wishing to pay their last respects at the Wat Chas pagoda in Phnom Penh.
A 38-year old suspect, Chuop Somlap, was arrested on Sunday after the shooting and admitted to killing Kem Ley in a dispute over money, the Interior Ministry said in a statement.
Some mourners were skeptical of the reason Chuop Somlap gave for killing Kem Ley.
"His killing is political," Sampoy Chansophea, a 24-year old supporter from Ratanakkiri province, said at the funeral. "Political killing has happened and it will continue to happen. Anyone who dares to speak out is facing death."
A court said on Monday that Chuop Somlap, whose name means "meet to kill", has not been yet charged.
Hun Sen condemned the attack on Monday and urged people to be calm during the investigation.
He said his government would be discredited for failing to guarantee the safety of citizens, but that people should refrain from making the killing a political issue.
"Politicians should not use this to instigate things that would lead the country into unrest," Hun Sen said.
Kem Ley was a frequent critic of Prime Minister Hun Sen, whose more than 30 years grip on power has been challenged by the rise of the opposition Cambodia Nation Rescue Party (CNRP).
Kem Ley's most recent critique of Hun Sen's administration was a commentary on a report by anti-corruption pressure group Global Witness, which accused the prime minister and his family of having amassed $200 million in business interests.
On Monday, people huddled under tents and in the shade of trees holding pictures of the popular commentator.
"I was shocked when I heard about the shooting," said Kem Ley's son, Kem Veasna Ranuch, adding that his father had never mentioned either the debt or Chuop Somlap.
Kem Ley is survived by four sons and a pregnant wife. Mourners gave donations to Kem Ley's family.
The United States was "deeply saddened" by Kem Ley's killing, said State Department spokesman John Kirby, urging a "thorough and impartial" investigation.
(Reporting by Prak Chan Thul; Editing by Simon Webb and Michael Perry)