JAKARTA — Indonesian environmental activist Muhammad Rosidi shudders as he recalls the horrific moment two men on a motorbike threw acid through the open window of his car as he was driving on Sumatra island in February.

He was instantly consumed by a burning pain as the corrosive liquid ate into his hands, legs and groin.

“I knew right away it was acid. It felt like being doused in boiling water,” the 43-year-old told AFP.

No arrest has been made weeks after the attack that Rosidi is convinced was triggered by his campaigning against illegal tin mining and smuggling in the Bangka Belitung islands off Sumatra.

He is one of an increasing number of activists and government critics rights groups say are being targeted in ever-more vicious attacks in the world’s third-largest democracy.

The latest victim was 27-year-old Andrie Yunus, an activist from the KontraS human rights group who risks losing vision in one eye after two men on a scooter threw acid at him while he rode a motorbike in the capital Jakarta last month.

In an environment Amnesty International described this week as “rife with repression of dissent”, protesters, journalists and even academics are also coming under threat.

“After the attack on Andrie, the threats actually increased... also death threats,” Bhima Yudhistira Adhinegara, executive director of the CELIOS economic think tank, told AFP of his own experience.

He is being targeted for critiquing government programmes including President Prabowo Subianto’s signature school feeding scheme, a major budget outlay.

A stranger recently texted Bhima to say that his name had appeared on the same hit list as Andrie’s.

“We’ve been stepping up security... adding more CCTV and body protection. When going out, we don’t go alone, we travel in pairs,” he said.