A new wave of ISIL suicide attacks, sniper fire, and roadside bombs targeting Iraq forces and their militia allies killed more than 30 fighters on Thursday in and around the city of Ramadi, a military source told Al Jazeera.

The heavy fighting comes after more than 50 Iraqi soldiers and pro-government tribal fighters were killed earlier in the week during attacks by the Islamic State of Iraq and the Levant group near the city, which lies just 100km west of Baghdad.

ISIL counter-attacks kill Iraqi soldiers

Earlier in January, the Iraqi army declared Ramadi liberated after a major offensive reclaimed government offices in the city centre.

But, since then, Iraqi forces have faced continued onslaughts from ISIL and fierce resistance in areas it holds in Ramadi's suburbs.

During Thursday's fighting, four suicide car bombers were killed by US-led coalition air strikes, but two others were able to plough into the main gates of an army division headquarters in Ramadi's al-Thirthar area, inflicting significant damage.

At least 17 Iraqi soldiers were killed and 46 wounded, including seven officers, the military source said on condition of anonymity, citing security reasons.

Another 15 Iraqi forces were killed and 20 wounded elsewhere in the city.

Ramadi, capital of Anbar province, fell to ISIL in May 2015 in an embarrassing setback for Iraqi forces.

Al Jazeera's Imran Khan and Osama Mohammed contributed to this report from Baghdad