A roadside bomb struck NATO-led International Security Assistance Force (ISAF) vehicle in Afghanistan's northern Kunduz province Sunday morning causing no casualties, a spokesman for NATO-led forces in Kunduz Lieutenant Colonel Webber said. "A roadside bomb went off near a vehicle of German troops with ISAF this morning outside Kunduz city the capital of Kunduz province causing no casualties but a military vehicle was damaged," Webber told Xinhua. This is the second attack on NATO forces in northern region over the past two days. In the previous similar attack three German soldiers sustained injuries when a roadside bomb struck a military vehicle in Wardoch district in northeast Badakhshan province on Saturday. More than 4,000 German troops have been serving in Afghanistan within the framework of NATO-led ISAF to help stabilize security in the post-Taliban nation. Taliban militants who largely rely on roadside bombings and suicide attacks have yet to make comments. Kunduz a relatively peaceful province until last year has been the scene of spiraling Taliban-led insurgency over the past several months. Taliban insurgents have vowed to speed up attacks against Afghan and NATO-led troops this year in Afghanistan.