LONDON (Reuters) - British Prime Minister David Cameron has called a meeting of his government's emergency Cobra security committee after the killing of a man in south London, his office said on Wednesday.
Britain's government convenes Cobra meetings only to deal with incidents that have implications for national security.
Media reports said a British soldier was killed in the incident in the Woolwich district in the southeast of the British capital.
"The prime minister says the killing in Woolwich is truly shocking and he has asked the home secretary (internal affairs minister) to chair a Cobra meeting," his office told Reuters.
At least one man was killed in the incident and two other people were shot by police officers at the scene, police said.
"A number of weapons were reportedly being used in the attack, and this included reports of a firearm," police said in a statement.
Security was tightened in the area immediately after the incident. Helicopters hovered above and nearby roads were sealed off by the police.
Earlier, a teacher at a local school told the BBC he saw a body on the road and afterwards heard gunshots. Photographs posted on social media showed at least two people on the ground who appeared to be injured, but no further details were immediately available.