The UK police have made another arrest on Monday, in connection with the attack on London underground train.

This comes barely a week after the arrest and charge of 18-year-old Ahmed Hassan for the same offence.

Hassan was charged on Friday with attempted murder and the use of explosives.

This time, the man arrested was a 20-year-old man in Wales. This brings the number of people in custody to four.

The man was arrested before dawn by counter-terrorism officers in the Welsh capital, Cardiff and has been taken to a police station in London for questioning.

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Police did not name the suspect but said he was arrested under the Terrorism Act.

Two other men, aged 25 and 30, who were arrested in Newport in Wales last week, are still being questioned.

Placed on a packed train during morning rush hour, the improvised device injured 30 people when it went off despite apparently malfunctioning.

The attack in Parsons Green, a quiet residential area, caused panic among commuters and some were hurt in a stampede as people fled the scene.

Britain has not been quite a safe place this year.

The Tube bombing was the fifth terror attack in the country in six months — four of them in London and one in Manchester — with the bloodshed claiming 35 lives.

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