Islamic State militants are mounting frequent guerrilla warfare-style attacks around a strategically important Iraqi city that U.S. military officials declared "clear" of enemy forces only five weeks ago.

The militant group , alternatively known as ISIS or ISIL, has not seized any new territory in and around Ramadi, the capital of Anbar province. B ut an unknown number of militants maintain a presence in the area and regularly conduct attacks, exposing the Iraqi a rmy's inability to keep the area secure.

"It's a manpower thing. The Iraqis have enough forces to launch these big offenses, but when they go on to the next fight, ISIS comes back. It's exactly what the Americans used to do before the surge [in 2007], the same kind of problem," said Joel Wing, an Iraq analyst and author of the blog Musings on Iraq.

The persistent ISIS presence around Ramadi has warranted almost daily air strikes on the area and highlights how tenuous the Iraqi army's hold on the city is. It also raises questions about the Iraqis' ability to secure other ISIS-held cities that are targeted for future operations — Mosul, in particular.

Since Feb. 9, when the city was deemed clear, U.S. Central Command has reported dozens of air strikes in the Ramadi area. The targets include:

38 ISIS tactical units.

24 ISIS fighting positions.

18 ISIS vehicles.

Four ISIS car-bomb facilities.

Five ISIS "bed down locations."

Two ISIS command and control nodes.

Two anti-air artillery pieces.

Iraqi forces, with the support of U.S. air strikes, mounted a long operation to retake Ramadi last year, first entering the city in December . In the weeks since Feb. 9, CENTCOM has reported on average of two or three daily air strikes there. That pace is down from five or six strikes daily in January, when the fight for the city was near its peak, according to CENTCOM data.

Iraqi flag raised over Ramadi after Islamic State forced from city Iraqi troops raise their national flag over a government facility in Ramadi on Dec. 28, 2015. The scene seemed to signify the Islamic State group's ouster from the strategically important city.

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A U.S. Defense Department spokesman in Baghdad downplayed the continued bombing, emphasizing that many of the air strikes reported to be targeting the Ramadi area are hitting targets outside the city center.

"Small teams of one or two terrorists, really guerrillas, if you will, will try to infiltrate into Ramadi," Army Col. Steve Warren said this week . "ISIL is not operating in the city . ... And we don't believe they've got the capability or the combat power to try and regain any type of a foothold .

"ISIL is trying to conduct disruption operations," he added, "... as Iraqi forces are continuing the very difficult and painstaking process of reducing the [improvised explosive devices] and the bobby traps and the mines that they have discovered . "This is a tactic that we've seen. We expected it. The Iraqis understand it and are dealing with it ."

Yet some military experts say the ongoing need for air strikes raises questions as to whether the tactical victory over ISIS in February will hold.

"Were they really defeated?" asked Christopher Harmer, a military analyst with the Institute for the Study of War in Washington. "ISIS fights as dismounted foot infantry and when they are defeated as individual foot soldiers, they turn into IED bombers and suicide bombers .

"Now the Iraqi security forces and the U.S. are facing individual, solo terrorists out there. And that’s a much more difficult problem set," Harmer said. Notably, the ISIS activity remains outside Ramadi's city center because the civilian population fled in December to escape the Iraqis' ground offensive and barrage of U.S. air strikes.

"There is nobody really back in Ramadi yet. It's still pretty much empty. So we have to wait and see what happens when people come back," Wing said.

A member of the Iraqi security forces stands guard as Sunni Muslim worshippers attend Friday prayer at the Dawla mosque in the city of Ramadi, the capital of the Anbar province, around 100 kilometres (60 miles) west of Baghdad, on February 5, 2016, which was recaptured from the Islamic State jihadist group at the end of last month. Months of fighting in Ramadi have caused extensive destruction, officials said, warning that it was too soon for civilians to return to the Iraqi city after its recapture from jihadists. Iraqi forces declared victory on December 27, 2015 in the Ramadi battle after wresting back control of the city's central government complex from the Islamic State group. / AFP / STRINGER (Photo credit should read STRINGER/AFP/Getty Images)

A member of the Iraqi security forces stands guard as worshipers attend prayer at the Dawla mosque in Ramadi on Feb. 5.

Photo Credit: AFP/Getty Images

Persistent threats in the Ramadi area are draining some of the Iraqi a rmy's time and resources from the effort to evict ISIS from Hit, a city about 35 miles to Ramadi's west. "Otherwise, those forces could be used in Operation Desert Lynx to more rapidly clear through the Euphrates River Valley," Warren said, referring to the Iraqis' effort to push west and seize more ISIS-held territory.

Ramadi sits on the primary route between Syria and Baghdad. It became a top priority for U.S. and Iraqi commanders last year after ISIS overran the city in May. That prompted the White House to authorize an additional 450 U.S. troops for Iraq in June. Most of them deployed to al Taqaddum air base near Ramadi.

Defense Secretary Ash Carter offered to provide Iraqi forces in Ramadi with more American combat advisers and close-air support using U.S. Army attack helicopters, but the Iraqi government declined that additional support.

The Iraqi a rmy's counterattack is cited frequently by U.S. and Iraqi officials as evidence of the force's will and capability to retake Mosul, a city in northern Iraq that is several times larger than Ramadi and the largest urban area controlled by ISIS.

"This is why Mosul is going to be so difficult, because if this pattern repeats itself , you are talking about a multiple-years-long operation," Harmer said.

U.S. military advisers have trained about 20,000 Iraqi fighters during the past year, but many of those Iraqi troops will not take part in Mosul operations because they are tied down elsewhere , Warren said.

"A lot of the fighters that we have trained are operating in Anbar and will continue to operate in Anbar. So [for Mosul] we have to train some new ones," Warren said.