Updated

A United States military plane has landed in Somalia's capital with medical and humanitarian aid supplies after Saturday's massive truck bombing killed more than 300 people.

A spokesman for the U.S. African Command tells The Associated Press that the charge d'affaires with the U.S. Mission to Somalia "declared that this disaster meets the criteria to warrant immediate U.S. government assistance" because of the widespread damage.

Another nearly 400 people were injured in the deadliest attack in Somalia's history and one of the world's worst attacks in years. Funerals have begun and dozens of critically injured have been airlifted to Turkey for treatment.

Somalia's government has blamed the attack on the al-Shabab extremist group, which has not commented.