Jakarta – State-owned PT Timah Tbk, the world's largest integrated tin maker, said protests at its main Bangka island plant had halted operations at two units, and warned the situation could be serious.

So far the potential losses are 1.5 tons a day, which a company spokesman described as not significant when compared to normal daily output of 100 tons. "What we are afraid of is that the protest would trigger more people in the area to start looting. This has already happened," Pudji Samekto said.

Starting on Monday, 250 ex-workers have protested against the outcome of talks over compensation with Timah management and the South Sumatra government. "The former workers blocked several installation units at two units in Toboali, Bangka ... They also stole some of the tin ore reserves in the area," the company said in a statement.

Timah, like many mining firms in Indonesia, has been hit by looting and clashes with locals mainly at its inland mining sites, hindering exploration efforts.

The company said many of its mining sites could not be exploited last year because of the conflicts, and some operations were abandoned after local communities took over the sites. "If this drags on we may have to relocate processing to other units," Samekto said, adding the company still had several other processing units in the island. Timah shares were trading at Rp2,275, up Rp20 despite the news, in late afternoon trade.