KABUL, Sept. 27 (Xinhua) -- Two soldiers of the NATO-led International Security Assistance Force (IASF) were killed and two others injured in southern Afghanistan, an ISAF statement said Thursday.

    The casualties occurred when some militants attacked an ISAF patrol base on Wednesday, the statement said.

    It did not say which province the incident occurred and the soldiers' nationalities.

    About 37,000 ISAF soldiers and 13,000 U.S.-led coalition forces are being deployed in Afghanistan to fight militant and keep security.

    They are frequently attacked by insurgents. Due to rising Taliban violence, over 170 foreign soldiers have been killed in Afghanistan this year.