Theresa May's thoughts are with killed, injured in "appalling incident"

Theresa May's thoughts are with those killed and injured in an attack close to parliament and the British prime minister is being kept updated with developments, her office said on Wednesday.

Four people were killed and at least 20 injured after a car ploughed into pedestrians and an attacker stabbed a policeman, in what police called a terrorist incident.

"The thoughts of the PM and the government are with those killed and injured in this appalling incident, and with their families," her office said in a statement.

"The PM is being kept updated and will shortly chair COBR," the statement said, referring to a meeting of the government's emergency security committee to be held later on Wednesday.