Attackers may be planning to strike in Algiers on Saturday, three days after twin suicide bombs killed 33 people in the Algerian capital, the US embassy said citing what it called unconfirmed information.
In a warden notice issued to US expatriates in the early hours of Saturday, the embassy said: "According to unconfirmed information, there may be attacks planned for April 14, 2007 in areas that may include the Algiers Central Post Office located in Rue Emir El Khettabi, and Algerian State Television Headquarters (ENTV), located on Boulevard des Martyrs, among others."
The embassy added it would be open for business as usual on Saturday but would be restricting the movements of its staff in light of the information it had received.
Two suicide bomb attacks killed 33 people and wounded more than 200 in the port city on Wednesday, raising fears that the north African country might return to the intense political violence that gripped the country in the 1990s.
Algeria descended into bloodshed in 1992 after the then military-backed authorities scrapped a parliamentary election which an Islamist political party was set to win. Up to 200,000 people were killed in the ensuing years of bloodshed.
That violence subsided in recent years following amnesties for insurgents, but rumbles on in mountains east of Algiers.
The Al-Qaeda Organisation in the Islamic Maghreb claimed responsibility for Wednesday's bombings, believed to have been the country's first suicide car bomb attacks
The claim could not immediately be verified but the group has taken responsibility for several deadly attacks on police, troops and foreigners in recent months.
The Organisation is made up of guerrillas based mostly in the Kabylie region east of the capital where the government is still trying to assert its grip. A section of the Organization is active in the country's Saharan south.
Formerly known as the Salafist Group for Preaching and Combat (GSPC) until it changed its name in January, it has shifted its strategy in recent months towards spectacular bombings in public places in towns and away from hit and run attacks on police in rural areas.
Interior Minister Nourredine Yazid Zerhouni has said the aim of the suicide blasts may have been to disrupt parliamentary polls due on May 17 and torpedo efforts to put a definite end to years of conflict between the army and Islamist rebels.