On June 11, the authorities arrested a fourth man, and the first Cambodian national, as part of a crackdown on suspected members of the radical Islamic group, Jemaah Islamiyah (JI).

The police arrested Sman Esma El, a 23-year-old local Muslim teacher at a Kuwaiti-funded Islamic school west of Phnom Penh. He was charged in the Municipal Court under Cambodia's anti-terror law on June 12.

Investigating Judge Oun Bunna indicated that the man was not the only Cambodian member of JI. The group was accused of carrying out the Bali bombing in October last year.

"I think there will be more arrests throughout the country ... including the leader of the group," he told reporters, adding that another three Cambodian Muslims and four foreigners would be targeted for arrest by the police.

The authorities arrested an Egyptian and two Thais last month at a Saudi-backed Islamic school. Bunna said the three had provided police with information which led to Sman Esma El's arrest, who had spent three years in Thailand studying at an Islamic religious school.