12 people arrested over London attack

British police say they have arrested 12 people in east London over the attack in the London Bridge area.

Police said in a statement that the arrests were made Sunday morning in Barking by counterterrorism officers.

Officials said that seven people died in the Saturday night attack and roughly 48 were wounded.

A British Transport Police officer and an off-duty officer were among the injured. In addition, three attackers were shot dead by police.

Police say the investigation is progressing rapidly.

Prime Minister Theresa May has blamed Islamic extremists.