Police are trying to negotiate with a man who has barricaded himself inside a house and may have doused it in petrol.
Officers were called just before 10am this morning and ten hours later are still at the home in Park Road, Windhill, Shipley.
The fire service is on standby after the man suggested he may have fuel inside the terraced house.
A police spokesman said officers responded to calls about concerns for the welfare of someone in the Windhill area at 9.50am today.
“Negotiations are continuing by the police trained negotiator with a local man who has barricaded himself inside the property,” he added.
A fire service spokesman said firefighters were assisting the police, but had no further details.
An eye-witness said there was a heavy police presence at Park Road, which is closed off at the junction with Carr Lane.