[UPDATE] London attack: Death toll rises to seven

London's Metropolitan Police chief Cressida Dick says authorities believe three attackers are among the seven people who have died.

Armed police stand over what is believed to be a suspect shot at the scene of a terror attack outside Borough Market in central London on 3 June, 2017. Picture: AFP

LONDON - Seven people are confirmed to have died in an attack by three assailants who drove a van at pedestrians on London Bridge before stabbing people in the nearby Borough Market area, London's Metropolitan Police chief Cressida Dick said on Sunday.

“It has now been confirmed sadly that seven members of the public have died. In addition, as you know, we believe, three suspects are dead,” she said in a televised statement.

Dick said police believed the incident was under control, but officers needed to conduct a thorough search of the area to ensure everyone was accounted for and no further suspects were at large.

"Our priority now is to work with our colleagues in the national counter-terrorism police network and also with the intelligence agencies and other security services to establish more details about these individuals who carried out the attack and the background to it," she said.

WATCH: An eyewitness describes what he saw when three terrorists struck on Saturday night.