Batam – About 1,000 workers at a Singapore-owned shipyard engineering firm in Batam went on the rampage on Tuesday, setting fire to an office, equipment room and several vehicles after security officers beat up two company employees.

The riot recalled a similar incident 18 months ago at another shipyard in the Indonesian province, Dubai-owned Drydocks World Graha.

Yesterday's incident, at the Nexus Engineering Indonesia shipyard in eastern Batam's Kabil industrial estate, sent about 30 security guards fleeing in terror.

An eyewitness said the trouble began when two workers showed up for duty without their eyeshields and name tags. They were then questioned and allegedly beaten up by security guards and a military officer inside the guard post.

About 500 Batam police officers – a quarter of the force on the island – were called in, and they managed to bring the situation under control last night.

Employees were asked to leave the compound after police secured it, said Nongsa sub-regency police chief, Major Robertus Heri. Work was expected to resume today.

Nexus Engineering Indonesia is a wholly-owned subsidiary of Singapore-listed Beng Kuang Marine, which provides services such as infrastructure engineering to customers in the marine and offshore oil and gas industries. The company could not be contacted for comment on Tuesday.

An eyewitness said yesterday's trouble began when two workers showed up for duty without their eye-shields and name tags.

They were then questioned and allegedly beaten up by security guards and a military officer inside the guard post. It is common for Indonesian companies to hire military officers to handle security.

When the two workers emerged from the guard post covered in blood, fellow employees confronted the guards.

Subandi, the coordinator of sub-contract employees at the company, told the Antara news agency that the guards were quickly overpowered by the enraged workers. He said the company has about 2,000 workers – including some Singaporeans – but not all of them were working yesterday.

The angry crowd stripped the military officer naked and threw his clothes onto the roof of the main building. They then beat up the guards, prompting the other security personnel in the compound to flee.

The burgeoning crowd then began damaging the premises, burning several guard posts and two motorcycles belonging to the security officers. A personal computer inside the post was also burned.

Altogether, five people were injured – the two workers who were assaulted in the guard post and the three security men who were beaten up by other workers.

Yesterday's riot was a smaller version of the one at Drydocks World Graha last year. That incident was sparked by a supervisor, an Indian national, who called Indonesian workers "stupid." It set off a rampage by about 5,000 local workers, who targeted the Indians working there.

The mob torched nearly 20 cars, and the authorities had to dispatch about 400 police officers to bring the situation under control. In all, nine workers were injured in the riot, five of them Indians, and operations were halted for a month.

The incident prompted the Indian expatriate association to issue an apology for what it called an "indecent statement" by one of its members. Police later identified Ghesa Prabaharan, 27, as the supervisor who made the offending remarks. He was charged with causing humiliation and hostility against the state.

Though reports at the time suggested that the riot was a reflection of brewing resentment among Indonesian workers at the shipyard over low wages and slights by Indian colleagues, the Indonesian government insisted it was an isolated incident. Manpower Minister Muhaimin Iskandar said the episode was purely a case of bad communication.