US-led forces have carried out a deadly offensive in Afghanistan. The Governor of Kandahar province says 60 alleged Taliban fighters have been killed in a ground and air assault. The US military puts the figure at 20, and says it is investigating reports of civilian casualties.Local officials say at least 16 civilians died. The Taliban claims all those killed were civilians. Observers say the US-led strike in the Panjwai district came after several days of some of the heaviest Taliban attacks since they were ousted in 2001. The surge in violence comes as NATO expands its peacekeeping force from 9,000 to 16,000. It will soon be taking over security responsibilities from US-led forces in the south. Security has been stepped up in southern and eastern regions because of increased Taliban attacks.