Iraqi security forces withdrew from three cities in Iraq's western province of Anbar, after the Sunni militants took control of a fourth strategic city near the border with Syria, a provincial police source said on Sunday.

The city of Rawa, some 275 km northwest of the Iraqi capital of Baghdad, and the nearby city of Aanah, are under the control of the Sunni militants who seized the police stations and government offices in the two cities without fighting late on Saturday, the source told Xinhua on condition of anonymity.

Later on Saturday night, the Sunni gunmen, including those who are linked to the Islamic State in Iraq and Levant (ISIL), an al- Qaida offshoot, took control of the city of Rutba, some 370 km west of Baghdad, the source said.

The insurgent groups also seized Albu Haiyat area and the small town of Jubba near the city of Hadithah, some 200 km northwest of Baghdad, as they are preparing for an attack to enter Hadithah, the source said,

Reinforcement troops have arrived in Hadithah since the early hours of the day, in an attempt to stop the march of the militant groups, the source said.

Early on Saturday, the Sunni militant groups took full control of the border city of al-Qaim, some 330 northwest of Baghdad, after fierce clashes with the troops, the source said.

Lieutenant General Qassim Atta and security spokesman of Prime Minister Nuri al-Maliki confirmed later on Saturday the fall of al- Qaim, but said security forces are fighting the militants in east of the city after they withdrew.

On Friday, the militants took control of the border crossing point with Syria which located just five kilometers west of al- Qaim, and also seized several border posts after clashes with security forces.

The Iraqi security forces are still controlling another border crossing point of al-Walid with Syria, as well as Tribil crossing point with Jordan, which located some 120 km west of Rutba, according to Interior Ministry spokesman Saad Maan.

Iraq has seen a deteriorating security situation since June 10 when bloody clashes broke out between security forces and hundreds of Sunni militants who took control of Mosul and later seized swathes of territories after Iraqi security forces withdrew from their posts in Nineveh and other predominantly Sunni provinces.