Kabul, Afghanistan ? A day after U.S. airstrikes killed up to 80 militants, another 19 people were killed in new attacks.

President Hamid Karzai ordered an investigation into the bombings on Monday that left at least 16 civilians dead.

In a statement, Karzai expressed “concern at the coalition forces’ decision to bomb civilian areas” at the village of Azizi in Kandahar province, but he also strongly condemned the “terrorists’ act of cowardice” in using civilians as human shields.

The deaths Monday and Tuesday brought to 305 the number of people killed in fighting during the last week. Most of the dead were militants. It’s the deadliest spate of fighting in four years and comes ahead of preparations for the U.S.-led coalition to hand over security operations in southern Afghanistan to NATO by July.