MOGADISHU, Somalia (AP) — The al-Shabab extremist group says a rare female suicide bomber used in the deadly attack in the office of Mogadishu's mayor was aiming for the American who is the new United Nations envoy to Somalia. He had left the office just minutes earlier.

The death toll in Wednesday's attack has risen to seven, and a hospital official says the seriously wounded Mayor Abdirahman Omar Osman is in a coma. He and other officials are expected to be airlifted to Qatar for treatment.

It was not clear how the bomber managed to enter the mayor's office as visitors are required to pass through at least four metal detectors. Some security officials said the attacker might have coordinated with corrupt officials, offering them bribes for access.