An Ipswich woman has described how the London bus she was on was stopped after those on board heard gunshots.
Jane Berry had been sightseeing in the capital when she became caught up in the commotion following an attack at London Bridge.
Police were called to a stabbing in which several people are understood to have been injured.
According to the BBC, The Met have said one man had been shot by police and it was treating the incident "as though it is terror related".
READ MORE: Police respond to 'major' incident on London Bridge
Speaking after the incident, Mrs Berry, who had been travelling to Trafalgar Square, said police cars were racing past and armed officers were shouting at people to "get back, get back!"
She said the bus had been stuck in traffic for some time when the driver told passengers there had been an "armed incident" and they had to get off.
While she herself had not heard gunshots, she said the driver and other passengers had.
At the scene she described a lorry facing the wrong way on the bridge and armed officers, police vans, helicopters and ambulances.
She added police were using tape to cordon off a large area.
"People are just hanging around, people are just mystified really," she said.
She said crowds of people, including tourists, didn't know where to go, adding London Bridge Station had also been closed.
She also described eight or nine police boats on the River Thames preventing travel along the waterway.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here