A mother and son from Chesterfield have told Peak FM they are stuck in the locked-down Shard building, close to where today's attack on London Bridge happened.
Alison and Ewan Walker have sent Peak FM photos from the building, which shows a number of police vehicles and helicopters surrounding the bridge.
Alison said: "We looked down at London Bridge and saw what we thought was a jackknived lorry, but then we looked on the news and found out that there had been an incident.
"We were a little bit concerned but then staff came round and said the Shard is on lock-down and we're not allowed to leave the building."
She added: "We can see lots of Police cars and all the buses and lorries are all stopped. A lot of people have been told to go back into the buildings so there's not a lot of people on foot.
"We've got two police helicopters up in the air right where we're sat so we're feeling quite safe up here."
- Police have confirmed a suspect has been shot and killed by officers.
- A number of people have been wounded.
- Detectives are treating it as a terror attack but are keeping an open mind as to the motive.
- The Metropolitan force has also confirmed that the man had a hoax device strapped to his body.
- Video on social media shows the moment he was confronted by members of the public and then police - with someone moving a very large knife away from him.
- London mayor Sadiq Khan's described the incident as horrendous - and says his heart goes out to those caught up in it.
- At the start of this month the UK's terrorism threat level was downgraded to "substantial" from "severe."