Thousands of subcontracted employees working for PT Nexus Engineering Indonesia in Batam went on the rampage on Tuesday morning, burning a company office.
It is the second such attack involving a ship-yard business in the province in 18 months.
Antara reported that the incident was sparked by a security officer who allegedly punched an employee.
Outraged employees soon ran amok, forcing the evacuation of a number of personnel as the mob burned an equipment check room and a motorcycle belonging to the security guard.
Subandi, the coordinator of subcontract employee at the company, said the incident happened so quickly “the security officers could not control the angry mob.”
He said the company hires 5,000 subcontracted employees though not all were present at the site on Tuesday.
Thousands were involved in the riot, he said.
Police have secured the scene.
Nexus, which also operates in Singapore, is yet to make a statement.