Land rights activists yesterday once again had their weekly “Black Monday” protest marches blocked by authorities.

It was the fourth installment of the protests, which encourage activists to don black shirts and call for the release of five current and former human rights workers imprisoned for allegedly bribing a witness in connection with a sex scandal involving opposition acting president Kem Sokha.

Four of the detainees are Adhoc officals, while the other is a former Adhoc official who is now deputy secretary general of the National Election Committee. They have been imprisoned for more than a month.

Protesters at Boeung Kak had black balloons snatched and their local march stopped by guards just before 7pm, according to Dy Thehoya, of rights group Central.

Meanwhile, about 30 protesters from the Phnom Penh airport’s “SOS” community were blocked on their path to Prey Sar prison by authorities and had banners ripped apart.

City Hall administrative director Mean Chanyada threatened legal action against protesters unless they ceased their activities. “We will continue to crack down . . . If they do not stop, we can make a lawsuit against them and send them to court.”

SOS protester Chray Nim said her group would protest until the five were released, adding that “local authorities always disappoint the people, because they are concerned about losing their power.”

Additional reporting by Erin Handley