While NATO has been endeavoring to sweep Taliban insurgents out from their hotbed in southern Afghanistan, the militants by influencing the northern provinces have opened a new front against the western military alliance.

The militants have stretched their activities in the relatively peaceful Faryab, Balkh, Kunduz and Baghlan provinces which link the Afghan capital Kabul to the former Soviet Republics of central Asia.

Militants on Thursday night attacked and injured three soldiers of the NATO-led International Security Assistance Force (ISAF) in Balkh province while Kunduz and Baghlan have been turned to the hub of insurgents.

Parts of Baghlan province, particularly Baghlan-e-Markazi district, has been the scene of almost continued skirmishes over the past couple of months.

In addition to Taliban fighters, militants loyal to dissident warlord and former Prime Minister Gulbudin Hekmatyar-led outlawed Islamic Party, the Hizb-e-Islami, are active in the strategically important Baghlan province.

An individual Al-Hadid who claims to speak for the outfit, in talks with media from undisclosed location said Saturday that Hizb' s men clashed with Afghan and NATO-led International Security Assistance Force (ISAF) troops in Kokchinar village Friday, killing two Afghan soldiers and four international troops but authorities rejected the claim as groundless.

A senior police officers in the province Zalmai Mangal confirmed the gun battle, stressing the militants were forced to flee as aircrafts pounded their hideouts.

Meantime, Taliban fighters attacked German forces in Shikhmir area of Chardara district Saturday morning and according to officials, there were no casualties on the troops.

Militancy has escalated in the north of Afghanistan amid U.S. and NATO's efforts to secure the second supply line through Russia and central Asian states in the wake of frequent attacks on NATO's logistic convoys in Pakistan.

Taliban insurgents, according to media reports, have carried out series of dreadful attacks against NATO's logistic convoys in Pakistan since early this year, during which scores of trucks have been destroyed and their drivers have either been killed or threatened of dire consequences if continue to supply fuel to the troops.

The militants have repeatedly attacked the NATO's logistic convoys passing through Pakistan into Afghanistan in Khyber Pass and Spin Boldak and according to media reports, only in late August Taliban loyalists attacked logistic convoy in Spin Boldak destroying over a dozen military vehicles and trucks.

Furthermore, the militants in attempt to mount pressure on the troops have closed down Khyber Pass seven times this year for NATO's convoy.

In order to adequately supply some 100,000-strong forces in the post-Taliban country, NATO's political leadership has looked for alternative route and approached Russia and central Asian nations.

NATO's spokesman James Appathurai said on Tuesday that agreement the military alliance needs "for the northern corridor will be reached soon."

Russia, according to the spokesman, has agreed to allow NATO to supply its troops in Afghanistan through the northern corridor which includes Russian soil and central Asian countries.

The northern corridor links Tajikistan and Uzbekistan to NATO- led ISAF forces' Headquarters in Kabul through Kunduz, Baghlan and Balkh provinces, while militants' presence in the region would serious affect the alternative supply line for troops in Afghanistan.

To control the situation, NATO's supreme commander in Afghanistan General Stanley McChrystal, according to media reports, has asked for additional 40,000 troops and adding that security situation was deteriorating in the north and western provinces.

Security situation has been deteriorating in the northern province, while the insurgents has gained foothold in the eastern Nuristan province.

The militants overran Kamdish district close to Pakistan's border after killing over a dozen troopers including eight U.S. soldiers overrun last Saturday.

While the fragile security situation has worried the Afghans and international community, U.S. Defense Secretary Robert Gates has noted that "any mistake to set a deadline to end U.S. military action and a defeat would be disastrous for the U.S."

Moreover, governor of Afghanistan's northern Balkh province Atta Mohammad Noor warned very recently that, "certain circles distribute weapons to irresponsible people in the north."

The security situation, if goes unchecked in the north of Afghanistan, would double NATO's challenge in achieving its mission in the militancy-plagued post-Taliban central Asian nation.