(CNN)The months-long fight for the key central Iraqi city of Ramadi now appears to be going ISIS’s way, with the Islamist extremist group capturing police headquarters, the Ramadi Great Mosque and even raising its trademark black flag over the provincial government building, sources said.

The ISIS push began Thursday, using armored bulldozers and at least 10 suicide bombings to burst through gates and blast through walls in Ramadi, according to a security source who has since left the city. Dozens of militants followed them into the city center.

Anbar Gov. Suhaib Al-Rawi said the offensive, including suicide-attacks with explosive-rigged cars near security posts, continued into Friday.

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