The Islamic State (ISIS/ISIL/IS) has claimed responsibility for a bombing attack that resulted in the deaths of nine people, which occurred in Egypt’s capital city of Cairo.

According to Reuters, the Islamic State confirmed its responsibility for the jihadi operation in a statement on its social media pages. It claimed that its militants were behind the deaths of six Egyptian police officers and three others on Thursday, after they were killed in a raid on a booby-trapped home near Egypt’s ancient pyramids.

“When the infidels entered, the bomb-rigged house was blown up,” a statement on a jihadist website attributed to ISIS said.

Thirteen more were wounded in the attack, according to Egyptian authorities, who said the Muslim Brotherhood had a hand in manufacturing the explosive materials.

“Police had information that a group of Muslim Brotherhood members were preparing to carry out aggressive acts in the coming days using explosives and crude bombs,” Egypt’s Interior Ministry said in a statement on its Facebook page. “This group was using an apartment in a Cairo building, and on Thursday night the police raided this apartment where they found a number of crude bombs.”

Islamic State’s Egypt affiliate has for the most part operated in the Sinai Peninsula. Its move towards Egypt’s capital may raise concerns about the security situation countrywide. The Sinai-based group behind the attacks was once known as Ansar Bayt al-Maqdis. Before Islamic State’s rise, the outfit had close ties to al-Qaeda and the Muslim Brotherhood.

Earlier in January, the Islamic State claimed responsibility for an attack on Israeli Arab tourists in Cairo.

And in August, the group again struck Cairo, detonating a massive car bomb that injured twenty-nine people.

The al-Haram neighborhood of Cairo, where the attack took place, is known to be rife with supporters of Egypt’s deposed former President Mohamed Morsi, who was part of the Islamist Muslim Brotherhood.

Muslim Brotherhood members have frequently attacked police over the past few years, rebelling against Morsi’s overthrow in 2013 by current President Abdel Fattah el-Sisi.

Monday will mark the fifth anniversary of the country’s 2011 Arab Spring protests, which led to the Islamist Brotherhood temporarily holding the reigns of power in the country. Egypt’s security personnel have raided over 5,000 apartments as a “precautionary measure” to ensure the Egyptian people’s safety, officials said.

“We are very concerned and will not allow protests,” an official told AP. “These movements are aimed at polarizing society and mobilizing the masses against the government.”