An influential rights group is urging donors to Cambodia to apply pressure on the government concerning the case of six labour union leaders accused of playing an active role in violent demonstrations earlier this year.

In an open letter posted on its website on Wednesday, Human Rights Watch (HRW) says donors should tell the government to end efforts to prosecute leaders of unions behind a nationwide garment strike over wages that lasted from late December to early January. Soldiers shot dead at least five people during a demonstration on January 3, as protesters set fires and threw Molotov cocktails at authorities.

The six union leaders face charges of intentional violence.

“Cambodian authorities are pursuing trumped-up charges against labor activists in an apparent attempt to get them to abandon demands for better pay and conditions,” HRW Asia director Brad Adams says in the statement. “This is just the latest government effort to scare activists and the political opposition into dropping plans to use protests to advance their causes.”

The statement names those to be called for questioning as union presidents Pav Sina, Ath Thorn, Chea Mony, Rong Chhun, Morn Nhim and Yang Sophorn. A Phnom Penh Municipal Court clerk on Wednesday confirmed all but Nhim.

The Garment Manufacturers Association in Cambodia (GMAC), representing more than 170 factories in the case, filed the suit in January.

With unions, the government and GMAC going through the process of setting next year’s minimum wage, Thorn, president of the Coalition of Cambodian Apparel Workers’ Democratic Union, said he thinks the summons coinciding with the wage negotiations is an intentional distraction.

“They are trying to use the court against us,” Thorn said.

GMAC secretary-general Ken Loo dismissed the notion of political motivations and said GMAC lawyers were looking into whether HRW’s call for pressuring the government amounts to obstruction.

“It’s quite stupid for HRW to be saying this,” Loo said. “They’re trying to get donors to pressure the government to drop the case – is that interfering with a case? That’s a chargeable offence.”