Sectarian violence reached Iraq’s capital city late Monday as Sunni militant forces grew closer to Baghdad, The New York Times reports.

Police found four young Sunni men shot to death in a mainly Shiite neighborhood, the report said. 

Members of the Islamic State of Iraq and Syria (ISIS), an al Qaeda affiliate, edged closer to the capital as they attacked a city 44 miles away.

{mosads}Armed militants attacked a police station in Baquba, which erupted into a three-hour gunfight, Brig. Gen. Jameel Kamal al-Shimmari, the police commander in Baquba, told the Times. Two officers were killed and five were wounded, according to the report. 

According to The Associated Press and the BBC, at least 44 prisoners were also killed in the attack, but it’s unclear exactly who was responsible.

Police officers at the station, which holds a small jail, told the AP they came under attack when the militants tried to free the detainees, who were suspected to be Sunni militants.

The officers said members of a Shiite militia killed the prisoners, but Iraq’s chief military spokesman, Lt. Gen. Qassim al-Moussawi, said ISIS attacked the facility. 

As the violence quickly advances toward Baghdad, President Obama is still mulling a more comprehensive U.S. response to break ISIS’s momentum. 

On Monday, Obama said he is sending 275 troops to Baghdad to protect the U.S. Embassy and personnel there.