CAIRO - 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 told 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. He did not disclose details.

Security officials with knowledge of the case said a Western embassy was the target, but did not have further information. They spoke anonymously because they were not authorized to talk 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.

The interior minister denied that al-Qaeda is active in Egypt, but said the three men were in contact with al-Qaeda militants abroad.

Egypt's security has sharply deteriorated in the last two years, with Islamic militants suspected of being behind cross-border assaults on Israel as well as a bold attack that killed 16 Egyptian soldiers in the northern Sinai Peninsula last year. Ibrahim told reporters that the men were trying to take advantage of the country's situation to "target innocent civilians and attack foreign diplomatic missions."

Ibrahim said one of the three men had received instructions from Assady to contact two members of the Nasr City terror cell.

Reflecting the deterioration in security, a U.S. citizen was stabbed Friday outside the heavily fortified U.S. Embassy in Cairo. Christopher Stone, who works at the American University in Cairo, "is doing well" and will be released from the hospital soon, the university said in a statement Saturday.