LONDON, Sept. 21 (Xinhua) -- British police on Thursday arrested a 17-year-old boy in south London in connection with the recent terror attack on a subway train, bringing the total number of arrests in the investigation to six.
The teenager was detained after officers executed a warrant in Thornton Heath in south London at around midnight on Thursday, police said.
A homemade bomb partially exploded last Friday on a rush-hour carriage of the District Line train at Parsons Green subway station in west London, injuring 30 people.
All the six suspects arrested for their possible role in the incident remain in custody under the Terrorism Act at a south London police station.
The Terrorism Act allows police to detain suspects without charge beyond the four-day cap for suspects of other crimes.
A 48-year-old man and a 30-year-old man were arrested on Wednesday in the Welsh city of Newport following the subway train explosion.
The third suspect, a 25-year-old who is reported to be a painter-decorator, was held in a counter-terrorism raid in Newport, South Wales, shortly after 7:00 p.m. BST (1800 GMT) on Tuesday.
Two other suspects -- Yahyah Farroukh, 21, and an 18-year-old man -- remain in custody after detectives were granted more time to question them over the bomb attack.
Scotland Yard said magistrates had granted warrants allowing the 18-year-old to be held until Saturday, and Farroukh until Thursday.
The news came as fresh CCTV footage emerged that appears to show the Parsons Green bomb suspect on his way to plant his homemade device.
The Islamic State claimed responsibility for the attack, the fifth terrorist attack in the country over the past six months.
Previous attacks in London this year at Westminster Bridge, London Bridge and Finsbury Park as well as a blast at an Ariana Grande concert in Manchester killed dozens of people and injured more than 150 others.
