Egypt’s interior minister said Saturday that security authorities have arrested three suspected al-Qaeda-linked militants who were planning to carry out suicide attacks on vital installations and an unspecified foreign embassy.

Mohammed Ibrahim said at a news conference that the men had been in contact with Dawood al-Assady, a leader of al-Qaeda in Southeast Asian countries such as Pakistan, and that the group was planning to attack government buildings and a foreign embassy, but he did not disclose details.

Security officials with knowledge of the case said only that a Western embassy was the target. They spoke on the condition of anonymity because they were not authorized to speak to the media.

The interior minister said authorities seized 22 pounds of ammonium nitrate, a key ingredient in homemade explosives. Security officials also discovered statements issued by al-Qaeda in the Islamic Maghreb, the group’s arm in North Africa, on one of the men’s computers with information on how to make bombs and rockets, and ways of collecting intelligence.

He said the suspects are also believed to have links with the Nasr City terror cell, which was broken up last year and its members arrested on accusations of plotting attacks against public figures in Egypt.

Egypt’s security has sharply deteriorated in the past two years, with Islamic militants suspected of being behind cross-border assaults on Israel, as well as an attack that killed 16 Egyptian soldiers in the northern Sinai Peninsula last year.

The interior minister named the suspects as Amr Mohammed Abu al-Ela Aqida, Mohammed Abdel-Halim Hemaida Saleh and Mohammed Mostafa Mohammed Ibrahim Bayoumi. Two of the men were detained in the northern coastal city of Alexandria, while the third was arrested in Cairo.

Reflecting the deterioration in security, a U.S. citizen was stabbed outside the heavily fortified U.S. Embassy in Cairo on Friday. Christopher Stone, who works at the American University in Cairo and was recently appointed as the U.S.-based director of the CASA program for intensive Arabic language study “is doing well” and will be released from the hospital soon, the university said in a statement Saturday.

The U.S. Embassy said the perpetrator, who was detained, claimed that his motivation was to seek revenge over U.S policies in the Middle East. “The [police] investigation, while still ongoing, has established that the perpetrator acted alone, and the incident was not tied to any larger conspiracy,” the embassy said in a statement.

Also Saturday, the retrial of former president Hosni Mubarak resumed in Cairo, with prosecutors requesting to present new evidence from a fact-finding commission’s report that claims the ex-leader had full knowledge of the extent of the violence used against protesters.

Mubarak is accused of collusion in the killing of nearly 900 protesters in the first days of the January 2011 revolt that unseated him.

Separately, Egypt’s top prosecutor ordered the release of one of the country’s most prominent activists only a day after ordering his arrest pending an investigation related to a protest against the interior minister.

Police officials and Egypt’s state news agency MENA say that prosecutors are referring Ahmed Maher to a misdemeanor court on lesser charges, including disrupting traffic during the March protest.

— Associated Press