Egyptian security officials inspect the site of a bomb blast in Giza on Dec. 9. (Khaled Elfiqi/European Pressphoto Agency)

A bomb blast killed six policemen and injured three others Friday in what was probably the deadliest assault targeting Egyptian security forces in Cairo in recent months, according to the country’s state-run news service.

The explosion occurred on al-Haram Street, a main road leading to Egypt’s famed Giza pyramids, according to the Middle East News Agency. It reported that the policemen were targeted but provided no further details.

Egypt’s Interior Ministry, which oversees the police and security forces, said in a statement that the bombing took place near “two security points” and that security forces were deployed at the scene after the incident. It said three of those killed were officers.

News agencies said the police officers were in two vehicles and were parked along the road at a checkpoint. Four civilians were also reported wounded by the explosion.

Later Friday, a recently emerged militant group called the Hasm movement claimed responsibility for the attack. The group has said it seeks retribution for the military overthrow of the Morsi government and the violent crackdown that followed. Egyptian security officials say that the group is aligned with the now-banned Muslim Brotherhood.

In a statement, the Hasm movement said “the blood of the martyrs will not go in vain, but rather this blood is the fuel to our revolution and a light that leads our resistance.”

Friday’s bombing came days after Egyptian security forces killed three members of the Hasm movement in southern Egypt, according to the Ministry of Interior.

The Hasm movement emerged in July, saying that it carried out the assassination of a top police chief. Since then, it has claimed responsibility for several more attacks, including assassination attempts against the country’s assistant prosecutor general and a senior cleric.

In May, gunmen attacked a bus filled with police in the Cairo suburb of Helwan, killing eight of them. The Islamic State’s affiliate in Egypt, based in the northern Sinai Peninsula, claimed responsibility for that attack.

Attacks aimed at Egypt’s military-led government have increased since the 2013 overthrow of elected President Mohamed Morsi and his Muslim Brotherhood. Judges and senior officials have also been targeted by radical Islamists, largely driven by the crackdowns on the Muslim Brotherhood by President Abdel Fatah al-Sissi’s government.

Last month, an Egyptian general was assassinated near his home in the northern Sinai, an attack that was also claimed by the Islamic State.