A homeless woman was arrested today on suspicion of starting a fire which engulfed a church, sources said.
More than 80 firefighters tackled the blaze at Great Commission Ministry Church in Shepherd's Bush Road, west London, after a call-out at 6.56am.
The fire started in a neighbouring homeless hostel before spreading to the church.
The church's roof was destroyed and the building damaged by water.
Scotland Yard said a 36-year-old woman was arrested on suspicion of arson and taken to a west London police station.
Emergency service sources said the woman was homeless and staying at the hostel when the fire broke out.
She had some superficial cuts on her arms but did not need medical treatment, according to the source.
Everyone staying in the hostel - a centre for homeless people with substance abuse and mental health issues - left the building and no injuries were reported, London Fire Brigade spokesman Tim Chidgey said.
"The fire on the first floor on the hostel was easily contained, but it has spread to the church.
"Evacuees are helping police determine how the fire began."