Counter-terrorism teams are searching a property in Crawley amid claims that a Briton staged a suicide bomb attack on a prison in Syria.
Officers are examining a house in Martyrs Avenue in Langley Green after reports that a UK jihadi, who used the name Abu Suleiman al-Britani, carried out the deadly bombing.
He is said to have driven a lorry into a jail in Aleppo and detonated a bomb last week, and is thought to be the first Briton to stage a suicide attack in the war-torn state, where increasing numbers of UK-born extremists have gone to fight.
More top news
Delays, diversions and cancellations caused chaos to services on South West Trains which were hit by signal failures in south west London.
During the attack Ione Wells' head was smashed against the pavement, her attacked grabbed at her chest with such force that it tore her bra.
The 17-year-old pushed her to the ground and smashed her head against the pavement, before grabbing at her chest.