Hundreds of protesters made their way onto the Jabiluka mine site and 112 were arrested after chaining themselves to vehicles and equipment, a Northern Territory police spokeswoman said.

Water pipes used for construction purposes at the site, 200km (125 miles) east of Darwin, were also cut, she said. "The people arrested were on the lease and they cut lines which supply water to the Jabiluka site," the spokeswoman told Reuters by telephone from Darwin.

Hundreds of environmentalists and traditional Mirrar Aboriginal people set up a picket in March outside the mine, which borders the World Heritage-listed Kakadu National Park. A spokeswoman for mine owners Energy Resources of Australia (ERA) said construction at the mine had been disrupted "for a while" during the latest protestaction. "At the moment they are back to work," the spokeswoman told Reuters.

Tuesday's arrests take to more than 340 the number of people arrested since the anti-uranium protest began.

ERA, which also owns and operates the nearby Ranger mine, said the arrests marked an apparent escalation in the protest. "Obviously today's actions represent a change in tactics by the protesters," said the spokeswoman, adding it was not yet known whether ERA would push for tighter security at the mine. About 180 protesters pushed their way through a thin police line outside the mine on June 3 and 106 were later arrested after police reinforcements arrived from Darwin.

Previous protests have focused on attempting to stop equipment and machinery from entering to the mine site, where construction is expected to last 18 months. Unesco said in June it would visit Jabiluka in the next few weeks to determine whether the mine poses a threat to Kakadu.

In October 1997 the Australian government removed 13 years of limitson new uranium developments. The Northern Territory government granted final approval for the Jabiluka mine on June 2, after which ERA began clearance and survey work on the site. Jabiluka is regarded by geologists as one of the world's richest uranium deposits with estimated reserves of 900,000 tonnes of uranium oxide.

The mine is expected to generate A$12 billion in revenue in its 28-year life, making Australia one of the world's leading uranium producers. Australia has about 30 percent of the world's uranium deposits but less than 10 percent of the market.