ISIS Islamists in Mosul
ISIS Islamists in Mosul Reuters

The Islamic State of Iraq and the Levant (ISIS) have conquered parts of the city of Baquba, locals told BBC News Tuesday, located just 60 km (37 miles) from Baghdad.

ISIS reportedly captured the main police station in the city, as well as several neighborhoods, locals said. The Islamists have seized on the police's weapons stockpile as well, stepping up the assault; however, security sources told the news outlet that Iraqi forces still had control over the city and outlying areas. 

ISIS continued to make advances toward Baghdad this week, capturing the nearby city of Tal Afar on Monday after seizing both Mosul and Tikrit last week.

The Islamist group has made a steady advance southward, analysts say, in conjunction with the Kurdish takeover of several cities in Iraq's northeast.

Map of ISIS advancements in Iraq. Circles show full control; red for ISIS, green for Kurds. Xs show where clashes between Iraq and ISIS have been reported Google Maps/Annotations from A7 staff

The ISIS has already controlled the Iraqi city of Fallujah for five months, and has also led one of the strongest rebel movements fighting Syrian President Bashar Assad in Syria. 

But last week's offensive has seen the ISIS claim a stunning number of victories in a lighting-fast takeover of the flashpoint region. 

So far, the Islamists have made a systemic advance from northern Iraq and southward. Last Tuesday, ISIS leaders seized Mosul; just 48 hours later, Tikrit - birthplace of former Iraqi dictator Saddam Hussein - fell to the terrorists.

Advancing toward Baghdad, large-scale clashes have erupted in Samarra; on the eastern front, Kurdish forces took Kirkuk to fend off the Islamist advance on Thursday

At least one report has suggested that ISIS forces have already entered Baghdad, but have made the decision to bide time before striking the capital city.