Iraqi security forces search for weapons during clashes with the al-Qaida-linked Islamic State of Iraq and the Levant (ISIL) in the city of Ramadi. Reuters

Gunmen have stormed a university in Iraq's restive Anbar province west of Baghdad and are holding dozens of students and staff hostage.

Iraqi police and army officials said militants stormed Anbar University, near the provincial capital Ramadi, on Saturday morning and detained hostages inside the university dormitory.

The militants are reported to be from the al-Qaida-linked Islamic State of Iraq and the Levant group, which has held parts of Ramadi for months.

The western Anbar province has been a focal point for Iraq's increasing sectarian violence, with Sunni militants controlling a number of areas. The violence prevented voting from taking place in the province during the 30 April parliamentary elections.

Prime Minister Nouri Malik's alliance won the elections but fell short of a majority. Opposition parties have blamed Malik for the violence, which has claimed more than 3,500 lives this year.

Malik, meanwhile, attributes the violence to external factors, such as the ongoing conflict in neighbouring Syria.

Earlier this week, militants launched an attack on the Sunni-dominated city of Samarra, 95km (60 miles) north of Baghdad.

Dozens of gunmen drove into the city attacking security checkpoints and police stations. Iraqi officials said seven members of the security forces were killed.

The Iraqi army sent in helicopter gunships and bombed the militants, but they remain in control of some parts of the city.

On Friday, dozens were killed in fighting between Sunni Islamists militants and Iraqi government troops in the northern city of Mosul.

Security sources said the militants advanced to Mosul from the north-west and killed at least four riot policemen and three soldiers. In southern Mosul, five suicide bombers stormed an arms depot and detonated their vests, killing 11 soldiers.

In the village of Muwaffakiya near Mosul, two suicide car bombs exploded, killing six members of the Shabak minority, which is often a target for Sunni Islamist insurgents.