Indonesian security forces fired on striking workers at Freeport-McMoran's gold and copper mine after a protest turned violent early Monday, killing one and injuring more than a dozen other people, officials said.

Two container trucks heading to the mining town from a nearby port were set on fire by striking employees, angry after learning the Phoenix-based company was bringing in replacement workers by the busload and moving them into their barracks. Black smoke billowed into the air, forcing some flight delays at the nearby airport.

Workers at the Grasberg mine in easternmost Papua province kicked off a strike on Sept. 15, demanding that their pay, which ranges from $2.10 to $3.50 an hour, be increased to between $17.50 and $43 an hour.

About 90 percent of the mine's 12,000 employees are taking part in the work stoppage.

Grasberg is one of the world's largest and most lucrative gold and copper mines, but has frequently seen protests over wages that workers complain are one tenth of what Freeport pays its miners in other countries.

The company -- which has come under fire in recent years for paying millions of dollars to Indonesian military and police to handle security -- also has been the target of angry demonstrations because of alleged pollution and the unfair distribution of profits.

Union leader Manuel Maniambo said thousands of striking workers were trying to prevent replacement workers from heading by bus to the mine, high up in Papua's rugged mountains. Others were upset after hearing their barracks, with their belongings still inside, had been taken over.

When blocked by security forces, striking miners became angry, throwing rocks and yelling insults.

The troops responded with gunfire, killing one worker and leaving another hospitalized in critical condition, said Maniambo.

Papua police spokesman Lt. Col. Wachyono said at least 11 other people were hurt, including six of his own men.

He blamed the striking workers, saying security forces had no choice but to fire warning shots after they became violent.

"It was complete anarchy ... they were attacking the police," said Wachyono, who like many Indonesians goes by only one name.

Freeport, based in Phoenix, Arizona, released a statement saying striking workers were to blame.

They have blocked roads, intimidated replacement workers and their families, as well as employees at bus terminals and barracks in recent weeks, the company said.

"We are continuing to work with the local police to deal with these acts of intimidation so that our workers located in Timika can exercise their rights to return to work if they so desire," it said.

"The individuals that are responsible for these illegal acts of aggression should be held accountable."

It's the second strike this year at the Grasberg mine. Workers walked off the job for eight days in July, also over low wages and the dismissal of union leaders. That cut the company's revenue by $30 million a day, analysts said.

Freeport said last month that the current strike was losing it daily production of 3 million pounds of copper and 5,000 ounces of gold.