BAGHDAD - Islamic State insurgents forced Iraqi forces to retreat on Wednesday after fierce fighting in the city of Baiji, close to the country's biggest oil refinery, a local official and tribal leader said.
Local police and anti-Islamic State fighters tried to repel insurgents for five days, but lack of support and ammunition had forced them to leave their positions in central Baiji to the militants, said Saad Thahir, a Baiji council member.
Before the latest clashes erupted last week, security forces and allied militias had stationed themselves inside the vital refinery facilities and left the defence of the city itself to under-equipped local police and Sunni tribal fighters.
"Top army commanders ordered troops to leave the city and take positions inside the refinery, which was given priority. They knew staying inside Baiji would help Islamic State to drag the army into a war of attrition," said an army major, on condition of anonymity.
Before they withdrew, Islamic State fighters had been aiming mortars and sniper fire at the army and militias from the city's outskirts.
"We are trapped inside the courthouse building and after all our appeals to the army to intervene to help us, we decided today to leave our positions in central Baiji, fearing falling in the hands of Daesh (Islamic State)," said Thahir.
"We called security commanders asking for support with arms and ammunition, but they refused. It's a shame to see Islamic State regain control of at least seven neighbourhoods of the city," Ghalib al-Nufoos, a Baiji tribal sheikh, told Reuters.
Last month, Iraqi security forces backed by Shi'ite paramilitary groups managed to break a months-long siege of Baiji refinery that had forced it to shut down operations.
In western Anbar province on Wednesday, Sunni militants set off a bomb that severely damaged a highway bridge in the city of Ramadi. Security forces and Islamic State have been battling for control of Anbar's capital since last January.
The al-Bu Risha highway bridge is a main supply route for security forces and is near the headquarters of Anbar's security forces, police and army said.