Islamic State militants have seized control of a military base in Hit, a town in western Iraq of about 100,000, allowing the militants to surround Ramadi, Anbar province's capital. The base was one of the Shiite government's few military outposts left in Anbar and gives the group, also known as ISIS, strategic control of area roads.

"The clashes started in early October, and now the armed groups have taken full control of the town," a university professor who left Hit three days ago with his wife and children told the Financial Times on the condition of anonymity. "The problem was the airstrikes. They were shelling houses and residential areas, which led to about 50 percent of the population fleeing."

ISIS' presence has increased by some 10,000 fighters sent from Syria and other parts of Iraq. The loss of the base in Hit can be seen as a “tactical withdrawal” by the Iraqi army unit assigned to defend it, a Financial Times security source said.

It is the latest military base to fall in Anbar, some 80 percent of which already was under ISIS control, the president of the Anbar Provincial Council said.