FARAH (Reuters) - Several Afghans working for a US-funded development project have gone missing after a Taliban attack overnight in western Farah province, the provincial police chief said. The official, Faqir Mohammad Askar, did not say how many were missing but he said two Taliban fighters were killed in the attack. One worker on the project, which is building a water reservoir, was wounded, Askar said. Taliban spokesman Qari Mohammad Yousuf said the insurgents killed eight workers and kidnapped as many as 20. Meanwhile, a soldier with the NATO-led International Security Assistance Force (ISAF) was killed by a roadside bomb in southern Afghanistan, ISAF said. It gave no other details. Meanwhile, an ISAF air strikes killed more than five insurgents in southeastern PAKTIA province on Saturday, ISAF said.