NOXIOUS fumes sparked a gas alert in Huddersfield.
The alarm was raised by worshippers at the Ahmadiyya Muslim Association mosque in Lower Fitzwilliam Street at about 9pm last night after an overpowering smell of fuel filled the building's prayer hall and cellar.
The street was closed by police at 9.30pm for about three hours while investigators tried to trace the source of the smell. Fire crews were today taking samples from the drains beneath the mosque.
The smell had been present all day but became more powerful as time wore on. This morning, the smell - similar to paint-thinner - still hung in the hall.
Missionary Ghulam Khadim, who lives above the mosque with his family of five, said: "There was the smell of diesel or petrol or something like that."
Workers from gas company Transco switched off the gas to the mosque and five neighbouring homes while the occupants of one house were evacuated for the evening. Staff then traced the smell to the drains.
Two Huddersfield fire crews accompanied by a specialist hazardous materials adviser were called out, quickly followed by Yorkshire Water workers.
Police asked for samples to be taken from the drains. Further samples were being taken today when Transco staff returned for more checks.