Counter-terrorism police were Wednesday investigating a fire that has destroyed a mosque in north London, dpa reported. Community groups have reported a rise in attacks on mosques and anti-Muslim hate speech since soldier Lee Rigby was murdered by suspected Islamic extremists in a London suburb last month. It was unclear whether the fire at the Al-Rahma Islamic Centre, which caused the two-storey building to partially collapse, was the result of arson. However, graffiti reading "EDL" was found on the building. The far-right English Defence League staged several marches across Britain after Rigby's murder, chanting slogans against Muslims. No one was injured in the fire, though one woman was treated for shock. Six fire engines and 35 firefighters were called out to tackle the blaze.