10:32 a.m.: London police said they are not aware of any hostages at this stage. The building search continues.
10:29 a.m.: London Metropolitan Police have arrested a 49-year-old man who allegedly carried a bomb into a building on Tottenham Court Road and threatened to blow himself up and take hostages.
A search of the building is underway, police said.
Earlier report: Tottenham Court Road, a major shopping street in central London, was closed Friday, buildings evacuated and police called in after a man allegedly carrying a bomb threatened to blow himself up, before taking four hostages.
Heavily armed police have since secured the site after learning from a woman that a mentally unstable man walked into her office with the intent to commit suicide.
London's Metropolitan Police issued a statement on Friday, stating that the man is believed to be 49 years old. They have yet to issue the name of the man but said police were called to the scene before noon.
Items, including electrical equipment, have been thrown out of a fifth-floor window, the statement read.
They have placed a 300-meter (1,000 feet) cordon around the area and a negotiator is on the scene.
There are no reported injuries at this time, the police said. It is unclear if there are other people in the building.
The UK's Telegraph reported that the man has been identified by an onlooker as Michael Green. A witness told the paper that he walked into the office of Advantage, a logistics company, and made the threat before allegedly taking the company's director and three salesmen hostage.
A woman claimed she was pregnant and pleaded for her life in order to escape, the Telegraph reported. Green reportedly failed a training course three times and returned to the building to demand that his money be returned, the paper added.
Abby Baafi, 27, is head of training and operations at Advantage. She explained the incident to the Telegraph as follows:
We were in the office and someone came in and we asked him what his name was and he said he was Michael Green. I recognized him because he was one of our previous customers.
He just turned up, strapped up in gasoline cylinders. Basically he threatened to blow up the office. He said he doesn't care about his life, he doesn't care about anything, he's going to blow up everybody.
He was specifically looking for me but obviously, I said my name's not Abby and I'm three months pregnant so he let me go.
Watch Baafi explain what happened to the Telegraph below: