Investigators probe Mosul blast as Iraqi forces push into Old City

Displaced residents who fled their homes are searched by Iraqi troops as Iraqi forces battle with Islamic State militants, in western Mosul, Iraq March 28, 2017. REUTERS/Suhaib Salem

MOSUL, Iraq/WASHINGTON (Reuters) - The senior U.S. commander in Iraq acknowledged on Tuesday that the U.S.-led coalition probably had a role in an explosion in Mosul believed to have killed scores of civilians but said Islamic State could also be to blame.

As investigators probe the blast, Lieutenant General Stephen Townsend strongly defended U.S. behaviour in the war and pushed back against accusations the United States had loosened safeguards meant to protect civilians as it ramps up the battle against Islamic State.