Twin car bombs near United Nations offices and an Algerian government building killed at least 45 people in the deadliest attack in the capital, Algiers, in more than a decade.

Many of the dead were students aboard a bus that was en route to a university when it was struck by the second car bomb.

The bomb near the United Nations building exploded around 9:30 a.m. on narrow Emile Payen Street, collapsing much of the Development Program’s white multistory building and hurling chunks of rubble across the street.

The blast blew out doors and windows of the buildings facing the Development Program building, including one housing the United Nations refugee agency. At least one staff member was killed there.

It was the first time that a recent bombing campaign by Islamist militants had touched the area, a quiet residential quarter of Hydra, which is home of many embassies and their diplomats on the so-called heights of Algiers.