Beirut: The Islamic State group sealed its capture of Ramadi after a dramatic pullout by Iraqi forces but was prevented by Syrian troops from taking over the heritage site of Palmyra.
Hundreds of fighters and civilians were killed in both battles, which also added thousands more families to the millions already displaced by conflict on either side of the border.
The effective loss of the capital of Iraq`s largest province marked one of Baghdad`s worst setbacks since it began a nationwide offensive last year to reclaim territory lost to the jihadists in June 2014.
"Anbar operations command has been cleared," Muhannad Haimour, spokesman and adviser to the provincial governor, told AFP.
Several security officials confirmed the retreat.
IS fighters, who already controlled most of the Anbar provincial capital, used a wave of suicide car bombings to take most of the city and raised their black flag over the provincial headquarters.
"Daesh has just taken full control of all main security bases," an army lieutenant colonel, who was among the troops that withdrew from the operations command centre, told AFP, using an Arabic acronym for IS.
Fighting took place in several neighbourhoods of Ramadi but reinforcements were too little too late as IS fighters used their momentum to complete their conquest of the city.
"We don`t have an accurate count of casualties yet but we believe at least 500 people, both civilian and military, have been killed over the past two days," Haimour said.
But he said that the city had not completely fallen, as fighting continued in some areas.
Prime Minister Haider al-Abadi said had approved sending forces from the Popular Mobilisation units (Hashed al-Shaabi) to try to rescue Ramadi.
The move marks a u-turn from the Sunni province`s previous opposition to resorting to the force, an umbrella for many Shiite militias.
"The provincial council of Anbar decided to call on Hashed al-Shaabi which operates under the umbrella of the commander in-chief of the armed forces," Mahdi Saleh al-Numan, the Anbar governor`s security adviser, said.
He added that the forces deployed would be drawn "from the disciplined brigades known for their honest work," suggesting that some Shiite militias would be barred.
Three days after IS supremo Abu Bakr al-Baghdadi tried to galvanise his troops in a rare audio message, the jihadists were denied a similar victory on the Syrian side of their self-proclaimed "caliphate".
On Saturday, the jihadists pressed their offensive and seized the northern part of the modern town of Palmyra, but were driven out by regime forces.
"IS`s attack was foiled,"said provincial governor Talal Barazi.
The Syrian Observatory for Human Rights monitoring group said nearly 300 people have been killed in four days of fighting.
The toll comprised 123 soldiers and loyalist militiamen, 115 IS fighters as well as 57 civilians, dozens of whom were executed by the jihadists, the Observatory said, quoting sources on the ground.
Barazi told AFP the army was "still combing the streets for bombs" after recapturing the northern districts.Observatory head Rami Abdel Rahman said the jihadists were still just a kilometre (less than a mile) away from the UNESCO-listed heritage site and its adjacent museum housing thousands of priceless artefacts.
Syrian antiquities chief Mamoun Abdulkarim expressed relief that IS, known for its wanton destruction of archaeological sites in territory it controls in Syria and Iraq, did not attack the site.
"We have good news today, we feel much better," Abdulkarim he told AFP.
UNESCO chief Irina Bokova has appealed to Syrian troops and jihadists to spare Palmyra, which the organisation describes as one of the most important cultural centres of the ancient world.
Governor Barazi voiced concern for the population, saying the fighting had forced civilians in the countryside to swamp Palmyra, home to 70,000 people.
IS posted pictures online of what it said was one of two checkpoints fighters seized inside Haql al-Hail gas field, triggering more clashes with pro-regime forces.
The Observatory director said a US raid late on Friday on one of Syria`s largest oilfields killed 32 IS members, including four leading officials.
"The US operation killed 32 members of IS, among them four officials, including IS oil chief Abu Sayyaf, the deputy IS defence minister, and an IS communications official," said Abdel Rahman.
US officials have said "about a dozen" people were killed in the operation by Iraq-based US commandos trying to capture Abu Sayyaf.
Abdel Rahman said three of the four leading officials killed in the raid were from north Africa, but that the communications official was a Syrian.
