Police said a man who bombed a London subway train bought the parts online. Police think an 18-year-old refugee left the bomb on a packed commuter train during the rush hour. It exploded at Parsons Green station at 8.20am. About 30 passengers had burns to their face and body. Police said the bomb didn't work properly and that more people could have been hurt. The bomb had knives, screws, glass and other dangerous things inside it.

The bomber bought many of the ingredients from Amazon. One ingredient was an explosive called TATP. It is called "Mother of Satan" because of its power. Police said the bomber wanted "maximum destruction". Reporters were shocked that Amazon's site directed visitors to other things that could make bombs. Amazon said it would stop this happening. It is reviewing its website to make sure its products are presented in a better way.