A suicide bomber blew up a refrigerated truck packed with up to a ton of explosives inside a military encampment southeast of the Algerian capital. 10 soldiers were killed and up to 35 wounded.
Al-Qaida's North African affiliate claimed responsibility for the truck attack, saying the truck carried more than a ton of explosives, the Al-Jazeera TV network reported, quoting a recorded message from an alleged spokesman for the extremist group.
The truck drove into the small post on the edge of Lakhdaria, some 80 kilometers (50 miles) from Algiers, as the doors opened in the morning for arriving personnel, the security official said. He was not authorized to discuss the bombing and spoke on condition of anonymity.
The official APS news agency reported eight soldiers killed and 23 injured, figures cited in initial reports. The security official confirmed that information, but said two more soldiers had died on the way to a hospital, bringing the total number of deaths to 10. Another 35 people were injured, the official said.
Interior Minister Noureddine Yazid Zerhouni, speaking at the parliament, downplayed the attack.
"Of course, we regret the attack this morning and the losses, but it is not a possibility that was excluded from the actions of terrorist groups," Yazid Zerhouni said.
The suicide bombing - a new tactic in Algeria - came the day of the opening of the Africa Games, one of the continent's biggest sporting events with venues in Algiers and the towns of Blida, south of the capital, and Boumerdes, to the east. Lakhdaria sits midway between Blida and Boumerdes.
A spokesman for the games, Abderaouf Abbas, also played it down. "These are events of secondary importance," he said, adding that security measures had been taken ahead of the event.
Soldiers fanned out throughout the region after the bombing, allegedly carried out by a youth who recently joined a holdout insurgency group linked to al-Qaida, the security official said.
Al-Jazeera played a recording from an alleged spokesman for the group, al-Qaida in Islamic North Africa. The channel did not give the spokesman's name or say how it obtained the recording.
"Our martyr, with God's help and might, managed to infiltrate the heart of the military camp ... and exploded in the middle of the courtyard," it said. The recording's authenticity could not be independently verified.
A second soundbite aired later identified the suicide bomber as "brother martyr Sohaib Abou Malih who drove a truck carrying more than one ton of explosives."
The attack was the biggest in Algeria since suicide bombings exactly three months ago in Algiers that killed 30 people and injured more than 200.
Until April, suicide bombings, a trademark of al-Qaida, had not been used in Algeria by Islamic extremists fighting an insurgency since 1992.
Al-Qaida in Islamic North Africa, formerly the GSPC, also claimed responsibility for those attacks, the largest directed at the prime minister's office in downtown Algiers.
The suicide bomber in the Wednesday attack was one of four youths who joined the group about a month ago, the security official said.
The explosion caused damage throughout the encampment and provoked panic in a region that saw widespread violence during the 1990s at the height of an Islamic insurgency and where security remains tight.
After the bombing, security was increased at the Algiers airport, where thorough checks of all cars and passengers were made, causing extended flight delays. Extra roadblocks went up around the capital.
Algeria has been seeking to turn the page on an Islamic insurgency that has killed as many as an estimated 200,000 people since the army called off elections in 1992 that an Islamist party was expected to win. While large-scale violence died down in the 1990s, scattered attacks by the al-Qaida affiliate have mounted in recent months.
Al-Qaida in Islamic North Africa claimed responsibility for a December attack that targeted a bus carrying foreign employees of an affiliate of the U.S. company Halliburton, killing an Algerian and a Lebanese citizen. The group has also threatened France.
Wednesday's attack came the morning after Nicolas Sarkozy paid his first visit to Algiers as France's president.
Last week, Algerian President Abdelaziz Bouteflika gave a saber-rattling speech to army officers on the country's Independence Day, denouncing "enemies of the people" trying to disrupt national unity.
That same day, a bomb hit the convoy of a top official in the Tizi-Ouzou region east of the capital. Security officials blamed the attack on al-Qaida in Islamic North Africa.
Thousands of athletes from 52 countries have come to Algiers for the Africa Games to compete in 27 different sports. The games are held every four years.
More than 8,000 police have been deployed since July 2 for the games at 36 sites used for the event, according to the daily Liberte. A total of 94 extra roadblocks were also planned for the event, the paper said.