Washington, July 10 (Xinhua) The US defence department is sending thousands of mine-proof vehicles to Afghanistan to protect its troops from improvised explosive devices, officials said.

More than 3,000 such vehicles have been shipped to Afghanistan, the Pentagon said Thursday.

The mine-proof vehicles are already in use in Afghanistan.

Mike Mullen, chairman of the US Joint Chiefs of Staff, told a press conference Wednesday that the improvised explosive devices became 'more and more sophisticated over time' and have become one of the biggest threats to the troops fighting the Taliban in Afghanistan.

He said the US military would build new versions of the mine-proof vehicle keeping in mind the Afghan terrain.

'From an equipment standpoint, there's no higher priority than to get these vehicles in theater as rapidly as we can,' Mullen said.