Sept. 22 (UPI) -- The homemade bomb that injured 30 people on a London subway train at rush hour last week was designed to inflict maximum damage, the Metropolitan Police's chief said Friday.
Commissioner Cressida Dick told a radio interviewer, "That was a very, very dangerous bomb. It partially detonated but it had a large quantity of explosives and it was packed with shrapnel. It could have been so much worse."
The bomb detonated Sept. 15 during the morning rush hour aboard a crowded train car at London's Parsons Green station. Witnesses described a "wall of flame" inside the car, and most of those injured suffered burns. None, though, were seriously hurt.
Authorities said the attack was terrorist-related.
Dick said the explosive device was placed in a white bucket, commonly used in the construction and painting trades, and hidden in a plastic shopping bag.
At least six people were arrested in the week after the explosion, but two arrested in Wales have since been released, Metropolitan Police said.
Searches in Thornton Heath, a London neighborhood, Surrey County and Newport, Wales, continue.
"I don't think there is a guiding mind behind all the people who have been attacking us this year, or indeed across Europe or in Australia or anywhere else," he said. "Different tactics will be used by different people at different times according to what they want to achieve, and we have to be prepared for everything."
Dick added that six potential attacks were stopped this year by British police, and last week's came as the Metropolitan Police faced cutbacks in funding and a rise in violent crimes. She said the force is under "huge strain" and noted that budget cuts make the duty of fighting local terrorism "not sustainable for any police service."