YEREVAN, MAY 30, ARMENPRESS. Iraqi forces have entered Islamic State-held Fallujah, one of their key strongholds in Iraq commanders say, according to AFP, reports RT.

On May 29, Iraq completed a troop buildup around the city, about 40 miles (65 kilometers) west of Baghdad.

"The operation to enter Fallujah began on [Monday] morning,” an Iraqi official told AFP.

An Iraqi military officer told Reuters the government's military unit is currently trying to advance in Falluja, with explosions and heavy gunfire reportedly heard in Falluja's southern Naimiya district.

Iraqi government-led forces launched an offensive to dislodge Islamic State (IS, formerly ISIS/ISIL) militants from Fallujah a week ago, and have been slicing through ISIS positions ever since. The terrorist group still controls territory in the north and west of the country, including Iraq's second largest city, Mosul.

Major Dhia Thamir told AP on Sunday that Iraqi troops had recaptured 80 percent of the territory around the city since the operation began last week. Iraqi Prime Minister Haider al-Abadi said, during a televised speech to parliament, that the "current second phase of the Fallujah operation" will last less than 48 hours.

The large-scale assault, carried out by the Army, police counterterrorism units, local tribal fighters and a coalition of Shiite Muslim militias, continues on all fronts around the city. Besides making vast gains in the north, forces, aided by US advisers, have also been advancing on the city from the Sinjar direction.

“We are moving in the right direction. We are killing those criminals,” a police unit fighter told RT last week, adding that approaches to the city are mined.

Fallujah, which survived some of the heaviest fighting of the 2003-2011 US-led military intervention, was the first city in Iraq to fall under IS control in January 2014. In late June, 2014, the extremists declared a caliphate in territories seized in Iraq and Syria.