Ansar Bayt al-Maqdis, now known as the Sinai Province after pledging loyalty to the Islamic State (ISIS), has claimed responsibility for a series of attacks on Thursday throughout the Sinai that resulted in the deaths of dozens.

The Sinai Province Twitter page claimed responsibility for the attacks, Reuters reports.

One of the attacks struck the headquarters of Egyptian government newspaper, al-Ahram. The paper’s employees said their office was “completely destroyed.” The terror group also bombed an Egyptian military base and hotel, which killed at least twenty-five and injured dozens more.

Later in the day, jihadists assassinated an Egyptian army major and wounded six more. Shortly thereafter, at Egypt’s Rafah border crossing area with Gaza, militants detonated an explosive device that killed an Egyptian police officer.

Egypt’s official military spokesperson blamed the Muslim Brotherhood and its “supporting elements” as primarily responsible for coordinating and carrying out the attacks. He said that the attacks were likely in retaliation for the Egyptian military’s recent strikes against jihadist groups in the Sinai.

Before pledging to the Islamic State, Ansar Bayt al-Maqdis was known for its closeness to Egypt’s Muslim Brotherhood. Since the fall of the Brotherhood from power, the jihadist group has killed countless Egyptian military and police officers. The group is said to be motivated by “avenging” the downfall of the brotherhood.

Ansar Bayt al-Maqdis borrows its slogan from a Koranic verse which was popularized by Muslim Brotherhood founder Hassan al-Banna. The founder of Egypt’s Islamic Jihad has alleged that the group has in the past been armed and financed by the Brotherhood. Furthermore, Egyptian anti-Brotherhood groups have previously described the Sinai terror organization as a “military wing of the Muslim Brotherhood.”

The U.S. State Department listed Ansar Bayt al-Maqdis as a Foreign Terrorist Organization (FTO) on April 9, 2014. In its designation as an FTO, The State Department describes the group as one that “shares some aspects of AQ (Al Qaeda) ideology.”