Malorees Junior School and Marylebone Boys' School have been evacuated, as well residents from their homes, this afternoon (Thursday March 2).
A rest centre has been set up at St Martin's Church in Kensal Green for residents in the Willesden Lane area by Brent Council, following the discovery at a building site at The Avenue, Brondesbury Park.
Officers from the police, London Fire Brigade and the council are all on the scene.
The army has been called as they are trained to deal with the situation and a team have arrived at the site, the council confirmed.
A 200 metre cordon has been put place and there are a number of road closures causing disruption to travel.
Motorists and residents are advised to avoid the area.
Buses have also been arranged ready to transport residents once the army has evaluated the situation.
Councillor Muhammed Butt, leader of Brent Council, said: “Council officers are currently making arrangements for our residents in the Willesden Lane area to make their way to a rest centre where they will be looked after until it is safe to return to their homes.
“I would like to thank these residents who have shown great patience during this time.
"We will continue to provide updates on the situation as soon as they come through.”
Police in Brent said they were called to the incident just after 11.30am.
Superintendent Nigel Quantrell of Brent Borough, added: "I would like to thank the community for their continued support as we and our partners deal with this incident.
"I can assure you that we are working very hard resolve the situation.
"The public's understanding and cooperation is deeply appreciated."
A helpline has been set up if you want to check on a resident who lives in the area, call 020 8937 5788
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