The system, armed with between three and five lasers, is designed to protect remote forward military bases from mortar, artillery or rocket attack. Such attacks were frequent against "forward operating" bases in Iraq and Afghanistan over the past decade.

The laser used in the test this month had a strength of 10 kilowatts (kW), but the programme would next use more powerful lasers of 50kW and then 100kW, officials said.

"If you are engaging a target at the same range, a 100kW laser will destroy the target in one-tenth of the time the 10kW would," said Terry Bauer, a programme manager at Boeing, which is the lead contractor involved in the Helmd project.

In the test, the laser was fired at 60mm mortar rounds, which have a range of between 1,800 metres and 2,700 metres. Officials said the laser scored a "significant success" against the mortar rounds and several drones.

"The system is capable of rapidly acquiring with the radar these very small targets and point a [small coin-sized] laser beam and destroy the targets while they're flying," said Mike Rim, another programme manager,

A more advanced version of the weapon would eventually be able to knock out objects moving much faster than the mortar rounds, such as cruise missiles, according to military officials.

The military has invested in a variety of laser weapons over the past several years with mixed results.

Next year the US navy is due to equip a ship converted into a "floating base", the USS Ponce, with a laser which would be capable of destroying small boats or surveillance drones.