Profile: Egypt's militant Ansar Beit al-Maqdis group
Ansar Beit al-Maqdis said it bombed the police headquarters in Cairo
Al-Qaeda-inspired militant organisation Ansar Beit al-Maqdis (Champions of Jerusalem) has claimed responsibility for the 24 January bomb attack on the police headquarters in the Egyptian capital, Cairo.
Initially, the group was known for launching attacks on Israeli targets and interests, but after the ouster of Islamist President Mohammed Morsi, it has started directing its violence against the Egyptian army and police.
Beginnings
Sinai-based Ansar Beit al-Maqdis started its operations immediately after the January 2011 uprising that led to the fall of the country's long-running ruler Hosni Mubarak.
Ansar Beit al-Maqdis first came into the limelight in July 2012 when it assumed responsibility for the blowing up of a pipeline that exports gas to Israel and Jordan.
A month later, the group said it had fired rockets from Sinai into the southern Israeli resort of Eilat, and in September 2012 Ansar Beit al-Maqdis claimed responsibility for attacking an Israeli border patrol in response to a US-produced film widely condemned in the Muslim world as having insulted the Prophet Muhammad.
Bomb and gun attacks
After the Egyptian military brought down the Muslim Brotherhood's President Mohammed Morsi in July 2013 and the clampdown that followed against his supporters, Ansar Beit al-Maqdis concentrated its attacks on the army and police.
The group has been involved in suicide bombings, drive-by shootings and assassinations.
In one of its most high-profile attacks, the group tried to assassinate Interior Minister Muhammad Ibrahim in September 2013, when his motorcade in Cairo was targeted by a car bomb.
Others include an assault on South Sinai's Security Directorate in October 2013, and an attack the same month on the military intelligence building in the Suez Canal city of Ismailiya.
'Palestinian links'
Some observers believe that Ansar Beit al-Maqdis has links to the Muslim Brotherhood and to Palestinian militant groups, especially the Hamas movement, which governs Gaza.
Brotherhood Without Violence, a recently-formed movement which includes alleged Muslim Brotherhood dissidents, claims Ansar Beit al-Maqdis is the Brotherhood's "military wing".
Nabil Naeem, former leader of the Egyptian Islamic Jihad militant group, has accused Hamas of funding Ansar Beit al-Maqdis.