PHNOM PENH (Reuters) - A Cambodian court on Saturday charged two journalists with espionage for filing news reports to a U.S.-funded radio station, which can carry a prison term of up to 15 years.

Prime Minister Hun Sen, the strongman who has ruled Cambodia for more than three decades, has taken a strident anti-American line in an increasingly tense run-up to a 2018 election and there has been a crackdown on critics, rights groups and independent media.

The United States announced it was ending funding for the election, and promised more “concrete steps”, after the Supreme Court dissolved the main opposition Cambodia National Rescue Party (CNRP) on Thursday at the request of the government, on the grounds it was plotting to seize power.

The party denied the accusation.

The two journalists, Uon Chhin and Yeang Sothearin, had in the past worked for the Washington-based Radio Free Asia (RFA) which broadcast in the Khmer language until it shut down in September.

The two were charged with “providing information that is destructive to national defense to a foreign state”, when they were caught filing stories to RFA, said Ly Sophana, a spokesman at Phnom Penh Municipal Court.

“They will be sent to an investigating judge for further procedures,” Ly Sophana told Reuters.

“NO TIES”

RFA has said it had no ties to the two journalists since it shut its Phnom Penh office in September.

“In charging two former RFA journalists with espionage, Cambodian authorities have opened the door to more serious forms of intimidation worthy of despots and dictators,” RFA spokesman Rohit Mahajan said in emailed comments.

A lawyer for the two said the charges were too serious and they had merely been doing their jobs as journalists.

“This is not dangerous to the country,” said the lawyer, Keo Vanny.

The charges carried up to 15 years in prison if the men were convicted, he said.

Hun Sen has been fighting a deepening war of words with the U.S. embassy and State Department over his government’s crackdown on the opposition.

CNRP leader Kem Sokha was arrested on Sept. 3 and charged with treason for an alleged plot to take power with U.S. help. He denied any such pot.

The U.S. State Department called on Friday for Cambodia to release him and reverse the decision to ban his party.

Western countries, which for decades supported Cambodia’s emergence from war and isolation, have shown little appetite for sanctions in response to the government’s crackdown, but the European Union has raised the possibility of Cambodia losing vital trade preferences.