Armed police have cordoned off a busy west London road after shots were fired outside a school today.

Witnesses reported hearing three shots outside the Kennet West Skills Centre in west London today, as a motorbike rider opened fire on a white car.

No students were in the school but building contractors working inside the building at the time of the incident spoke of how they ducked for cover after hearing the gunshots.

A witness said someone involved in the crash, possibly the gunman, ran into the building after the white Volvo crashed into the tree near the school.

An armed police officer is seen crouching outside the school after there were reports of gunshots earlier today

A cordon of around 50 metres has been put in place around the school in west London today

The driver's side window has been shattered during the incident

An empty shell casing is pictured beside the 'A' at the scene

Another scooter was also said to be driving with the bike involved in the shooting but sped off from the scene.

Pictures from the scene show the driver's seat of the white Volvo shattered and empty shell cases on the floor next to the vehicle.

Sources told MailOnline the white Volvo was a rental vehicle and the incident is believed to be gang or drug related.

Nick Purnell, who was working inside the building at the time of the shooting, said he was forced to hide in a cupboard after hearing gunshots at around 4pm.

The 42-year-old told MailOnline: 'It was a heart-pumping moment. My first reaction was to duck, but then I realised there was glass in front of us so I had to run.

'There were three of us working in one of the classrooms at the time and we all just ran out. My mate hid in a disabled toilet while me and the caretaker hid in the cupboard, and that's where I called the police.

A motorbike is left turned on its side near the scene of the incident in west London today

The white car which crashed into the tree is inside the police cordon

Around 10 police vehicles are said to have been dispatched to the scene

The Metropolitan Police confirmed that 'evidence of a firearm discharge was found'

'We waited until police arrived at the scene but then we managed to get out.'

Mr Purnell told MailOnline the person he believed to be the shooter was a black man in his early 20s or late 30s, wearing a blue striped top. He said that he entered the main entrance of the school and turned left down a corridor.

'I didn't hear any shouting after the shooting but people in the houses above were banging on the windows. It all happened so quickly,' Mr Purnell added.

Oliver Holder, 35, arrived at the scene shortly after hearing reports of the shooting.

Mr Holder, who works as a photographer, said police had put a large cordon of around 50 metres around the school and that around ten police vehicles, unmarked cars and a helicopter were dispatched to the scene.

He said: 'I was driving home and that is when I found out about the shooting. I live not far away from the area and it's not the first time this has happened.

'Last year a girl died after being shot on Malvern Road. Another person was shot on my road, this kind of stuff happens quite a lot now.

'This keeps happening but because we come under the borough of Westminster, we don't get the proper resources to deal with the problem.'

Police helicopters are said to be circling the Kennet West Skills Centre

The Metropolitan Police told MailOnline 'evidence of firearm discharge' was found at the scene.

They added there were no reported injuries and no arrests had been made.

A Metropolitan Police spokesman said: 'Police were called on Monday, 20 August at around 16:10hrs to reports of shots fired in Kennet Road, Westminster W9. Officers and armed officers attended.

'No reported injuries. Evidence of a firearm discharge was found.

'Officers with the support of the National Police Air Service are searching the area.

'No arrests. Enquiries continue.'