Medical officials put the death toll from the explosions in Algeria's capital city at more than 60, although Algerian Interior Minister Yazid Zerhouni confirmed 22 dead and 177 injured.

Zerhouni blamed the attacks on the local branch of al-Qaida.

The bombs detonated just minutes apart in two separate locations that were heavily policed. One exploded near the constitutional court in the busy central al-Biar area, blowing apart a passing bus carrying university students on their way to a nearby law faculty.

Another bomb ripped through the front of the U.N. High Commissioner for Refugees (UNHCR) building in the capital's Hydra district, where the finance and energy ministries as well as diplomatic missions and residences are located.

The UNHCR said 10 of its Algerian staff were among those killed in the explosion that Zerhouni said was triggered by a suicide bomber.

Despite an ongoing crackdown on suspected al-Qaida elements in Algeria, in which the authorities claimed to have foiled terrorist plots and seized caches of weapons and explosives, the deadly attacks show that the group is still effective and could plunge Algeria into renewed violence reminiscent of the past it has struggled to put behind it.

World leaders strongly condemned the attacks.

While there was no immediate claim of responsibility, security experts said the attacks had the signature of al-Qaida in the Islamic Maghreb, the new name for the Salafist Group for Preaching and Combat that pledged allegiance to Osama Bin Laden, using al-Qaida's suicide bombing tactics.

The group claimed responsibility for a series of attacks this year on police stations, army barracks, public officials, and Western personnel killing some 100 people.

Arab experts on Islamic groups suggest that the al-Qaida branch - assuming it carried out the bombings - wanted to send political and security messages to the Algerian government of President Abdel Aziz Bouteflika through the timing, locations, targets, and tactics used.

Algerian analysts linked the eleventh day of the month to carry out the two attacks in Algiers to the Sept. 11, 2001, attacks on New York and Washington, which unleashed the U.S.-led war on terror that critics say has only strengthened the al-Qaida network and increased its activities worldwide.

Among the attacks claimed by al-Qaida this year in Algeria, one took place April 11 killing 33 people in Algiers and another July 11 when a suicide bomber detonated an explosives-laden truck near a military barracks in eastern Algeria, killing eight people and himself.

Security experts say the group is seeking to demonstrate it has sufficient "operational military skills" to penetrate high-security areas in the capital, which had been kept largely free of violence during a decade of conflict between Islamist militants and state forces.

They argue that in targeting the UNHCR the perpetrators might not have been deliberately attacking an international agency, so much as demonstrating their capability to hit any target they chose in spite of increased security measures and captures of their leaders.

Algerian commentators said on Arab television news channels that al-Qaida in the Maghreb may also have intended to send a political message to Bouteflika by bombing near the constitutional court, which is debating the possibility of amending the constitution so that the president can run for a third term.

In addition, the recent municipal elections dealt a blow to the conventional Islamist groups as they failed to win more than 10 percent of the local council seats, indicating a substantial regression of the Islamists' political status in Algeria. The local al-Qaida attacks may be an attempt to present the group as an alternative to the declining traditional Islamists.

Algerians are still recovering from 10 years of violence that erupted in 1992 after the army-backed government canceled general elections that the Islamists were winning. And people do not want to see their country being swept up into another wave of bloodshed like the past conflict which is estimated to have left more than 100,000 people dead.