BAGHDAD — Iraqi forces evacuated dozens of families from Ramadi on Wednesday, but progress to retake the city from the Islamic State was complicated by the presence of civilians and booby traps.

Eid al-Karboly, a spokesman for the provincial council of Anbar, said that about 150 people had managed to cross the battle lines to reach Iraqi forces. However, thousands of others are still believed to be inside.

Iraq’s military on Tuesday launched an offensive for the center of the city, about 80 miles west of Baghdad, after besieging the militants downtown. Iraqi commanders have said it is only a matter of time before the city falls, predicting its recapture by the end of the year – a win that would give Iraqi forces a much-needed confidence boost.

But the militants have had seven months to dig in since they captured Ramadi in May and have built hidden tunnels between houses and planted bombs along the streets, according to U.S. and Iraqi officials.

“Our forces are advancing from all axes, but it’s an irregular battle,” said Brig. Gen. Ahmed al-Belawi, head of the province’s local police force. “It’s a battle between houses where everything is rigged with explosives, even the trees.”

Belawi said the evacuated civilians would be taken to a camp near Habbaniya army base, where they would undergo security checks to ascertain whether any Islamic State loyalists were among them.

“They were in a state of panic,” Karboly said. The Iraqi military dropped leaflets on the city last week, imploring civilians to leave, but the Islamic State has prevented them from doing so, while fleeing families risk crossing an active war zone.

Estimates of the number of civilians remaining in Ramadi vary widely. Col. Steve Warren, a U.S. military spokesman in Baghdad, said Tuesday at a briefing that “tens of thousands” could still be in the city.

Their presence complicates the U.S. air support that Iraqi forces have heavily relied on as they have progressed.

“The families were the reason for the delay in the operation,” Lt. Gen. Abdul Ghani al-Asadi, the head of Iraq’s special forces, said in an interview broadcast on state television. He said his troops, who have spearheaded the offensive from the south of the city, are now in the al-Thubat neighborhood after crossing a canal to storm the city.

The bridge was supplied by the U.S. military, which also trained Iraqi forces on bridging operations, Warren said. There is still a lot of “dense terrain” to be negotiated, he said.

The Iraqi military said in a statement that it had repelled a suicide bomb attack in the city on Wednesday. It said that 10 militants were killed, but did not indicate whether there were any casualties among Iraqi forces. U.S. officials estimate that between 250 and 350 militants remain in the city.