Accra, Jan 20 (IANS): Seven illegal miners were killed and one seriously injured during a gun battle with the troops in western Ghana, the military said.

The gun battle took place in Obusai, a town in the western African country's Ashanti Region, on Saturday when some 60 illegal miners breached AngloGold Ashanti mine's security fence to enter the Deep Decline care of the mine and opened fire on the military stationed there, the military said in a statement on Sunday.

According to the statement the illegal miners were wielding locally manufactured rifles, pump-action guns, gas cylinders, knives, heavy-duty industrial bolt cutters, axes and machetes, Xinhua news agency reported.

"The troops returned fire in self-defence. The shootout led to the death of seven illegal miners and one seriously injured. The remaining illegal miners bolted," it said.

"A soldier who was also hit by pellets from a pump-action gun and got injured has been treated," it added.

Ghanaian President John Dramani Mahama has ordered an immediate investigation to determine the circumstances surrounding the clashes and ensure that any individuals found to have acted unlawfully are brought to justice.

Security agencies have been deployed to restore calm in Obuasi -- one of the oldest gold mining towns in the world -- and implement measures to prevent similar incidents.

The Johannesburg-listed miner owns the Iduapriem and Obuasi mines in southern Ghana. The two mines produced more than 490,000 ounces of gold last year.

Over the past few years, the Ghanaian government has ramped up its efforts to tackle illegal mining, not least by dispatching security agencies to protect the mining concessions for their owners.