US-led airstrikes 'key factor' in battle

US-led air support broke the deadlock in Iraq's operation to retake Tikrit from the Islamic State group, a senior military official in the coalition carrying out the strikes said on Thursday.

"Air support became the key factor in this," the official told AFP by telephone.

Iraqi forces still would have been able to retake Tikrit without the air support, "but it would probably have taken a little longer," the official said.