Surabaya – The Indonesian army more than doubled its presence at a strike-hit Surabaya factory complex on Thursday as a separate union protest gathered around the local parliament.

The army feared that three-day-old strike and the union protest could merge into riots, military sources said. The 4,000 strikers are demanding higher wages, an increase in food and transportation allowances and shorter working hours. The number of soldiers deployed at and around the factory complex rose from about 100 to more than 200 on Thursday.

On Monday, 10,000 workers from another plant, the Kasogi shoe factory, descended on the main streets of Surabaya, Indonesia's second largest city. More than 200 members of the Indonesia Labour Prosperity Trade Union (SBSI) gathered at the local parliament on Thursday. They demanded a 20 percent workers' stake in every Indonesian company, the formation of a national labour council and the revocation of a law that forbids the formation of labour unions.