Kabul - Two Afghan soldiers lost their lives in a mine blast in southern Afghanistan, while at least 45 Taliban militants were killed in separate incidents in the region, officials said Wednesday.

Two soldiers were killed and four others injured in a roadside bomb blast in Shinkay, a district in the southern province of Zabul on Tuesday, the Defence Ministry said.

Taliban roadside bombs are responsible for the deaths of three quarters of Afghan and international forces killed this year, Afghan and NATO officials said. The number of roadside bombs has increased significantly over the past months.

Meanwhile, Afghan security forces backed by coalition troops killed 30 Taliban and injured 20 others Tuesday in the southern province of Uruzgan's Chora district, the Interior Ministry said.

There were no casualties among the forces, the statement said, but did not give more details about the operation.

Eleven other Taliban were killed in a fight with Afghan security forces in Ajristan district, Ghazni province.

Four militants died when the bomb they tried to plant on a road in Zherai district of Kandahar province went off prematurely, an army statement said. Both incidents took place Tuesday.

Afghan and NATO troops have increased operations against the resurgent Taliban in the past weeks in a bid to strike deeper into Taliban territories and push them back before the winter snowfalls limit military operations.

Eight years after the fall of their regime, the Taliban claim to be more powerful than ever and the militant group operates in almost all provinces of the war-torn country.

The insurgents' growing strength and mounting fatalities among the international forces, which have surpassed 400 this year, have forced NATO top commander US General Stanley McChrystal to ask for up to 40,000 extra troops.

More than 100,000 international troops are stationed in Afghanistan, but there is mounting doubt in Afghanistan about their determination to fight the militants in years to come.

In a move to energize the morale of the alliance, Britain has agreed Wednesday to send 500 more troops, taking its overall deployment to 9,500 military personnel.

Prime Minister Gordon Brown told parliament that his country would not send more troops to Helmand, where they are stationed, unless the Afghan government provides more of its own troops for training and fellow NATO governments also increase troop numbers.

US President Barack Obama is also rethinking his strategy for the Afghan war.

Obama is reportedly weighing options given to him by his security advisors over whether to send more soldiers to meet McChrystal's demand or to scale down troop levels and focus on counter-terrorism operations on the Afghan and Pakistan border, where the militants and fighters of the al-Qaeda terror network are deeply entrenched. (dpa)