Forces in Iraq and Syria are bolstering their offensives on the Islamic State of Iraq and the Levant (ISIL) group, in a bid to retake key cities in both countries.
Iraqi security forces and Shia fighters renewed efforts to retake the western Iraqi city of Ramadi on Monday, as ISIL poured more fighters into the city that it claimed a week ago.
Police sources said Iraqi forces had regained ground east of the city since launching a counteroffensive on Saturday, and on Monday has retaken parts of al-Tash, 20km south of Ramadi, which lies only a short distance from Baghdad.
Ramadi residents said trucks carrying ISIL fighters arrived on Sunday evening before spreading out across the city.
Syria launches air strikes
In Syria, the Syrian air force launched strikes on Monday at buildings captured by ISIL in the historic city of Palmyra.
ISIL has reportedly killed hundreds of people since it moved into the Palmyra area 10 days ago, and its occupation of the city has raised fears that its fighters will destroy its famed Roman ruins.
Syrian state TV reported that about 400 civilians had been killed by the group since Wednesday, while activists in Palmyra said ISIL fighters hunted down President Bashar al-Assad's troops and loyalists, killing up to 300 of them.
The seizures of Iraq's Ramadi and Syria's Palmyra were the group's biggest successes since a US-led coalition launched an air war against it last year.
Criticisms of strategy
The near simultaneous victories against the Iraqi and Syrian armies have forced Washington to examine its strategy, which involves bombing from the air but leaving fighting on the ground to local forces.
In a sharp criticism, Ashton Carter, the US defence secretary, on Sunday accused the Iraqi army of abandoning Ramadi to a much smaller enemy force.
"The Iraqi forces just showed no will to fight," he told CNN's State of the Union programme.
However, on Monday, both Iraq and Iran hit back against Carter's criticisms, with an Iranian general going as far as saying the US had "no will" to fight ISIL.
In Baghdad, a spokesman for Iraq's prime minister, Saad al-Hadithi, suggested Carter had "incorrect information", while General Ghasem Soleimani, the head of the elite Quds forces in Iran's Revolutionary Guard, said US and other forces were failing to confront ISIL.
"Carter was likely given incorrect information because the situation on ground is different," Hadithi told the Associated Press. "We should not judge the whole army based on one incident."
Hadithi said the Iraqi government believed the fall of Ramadi was due to mismanagement and poor planning by some senior military commanders in charge. However, he did not elaborate, nor has any action been taken against those commanders.
The general in charge of Iran's paramilitary activities in the Middle East, Soleimani, who is often seen on the battlefields of Iraq, said: "Today, in the fight against this dangerous phenomenon, nobody is present except Iran."
Meanwhile, in a move that could mark an expansion of US involvement in the conflict, Turkey said it and the US had agreed in principle to give air support to some forces from Syria's mainstream opposition.