There was no immediate claim of responsibility. Algeria's al-Qaida affiliate, al-Qaida in Islamic North Africa, is known to be active in the area.
The French engineer, working on a project to boost the number of rail lines at the station, was killed as he prepared to leave the site in a car, said the official, who spoke on condition of anonymity because he was not authorized to talk to media. The man's Algerian driver was also killed. France's Foreign Ministry said it was in contact with Algerian authorities about the attack but provided no other details.
The second bomb came about five minutes later. Eight soldiers and three firefighters were killed in that explosion, the official said. Several others were wounded, though the exact number was unclear.
The North African nation's Islamic militants have mounted several attacks over the past week. On Wednesday, a suicide attack on a military barracks and a second bombing at a cafe shook a beach neighborhood outside the Algerian capital, wounding six people. A day later, a roadside bomb killed six soldiers in the city of Boumerdes.
The attacks of the past week have come as Algerian President Abdelaziz Bouteflika prepares to inaugurate an international trade fair Monday outside Algiers, a high-profile event that will draw members of foreign governments.
Though Algeria has battled an Islamic insurgency for years, the number of attacks has risen dramatically since the country's main militant group vowed allegiance to al-Qaida in 2006.
Most of the country's bombings have been claimed by al-Qaida in Islamic North Africa, formerly known as the GSPC. The group grew out of an insurgency that raged in the country in the 1990s. The violence, which has left as many as 200,000 dead, was prompted by the army's cancellation of legislative elections in 1992 that an Islamist party was poised to win.
Many attacks in Algeria have targeted the national security services and military, while others have struck foreigners. Sunday's attack was apparently crafted to hit both of those targets. In December, a double suicide bombing in Algiers killed 41 people, including 17 U.N. workers. In April 2007, coordinated suicide strikes against the main government offices in central Algiers and a police station killed 33.