The 17-year-old boy was detained at a residential address in north London on Thursday as part of an investigation related to Islamist extremism, the Metropolitan Police said.

The force said he was questioned at a south London police station on suspicion of several offences, including being involved in the "encouragement of terrorism".

He has now been bailed until a date in February.

Commander Dominic Murphy, head of the Met's counter-terrorism command, said following the arrest: "We have officers working around the clock to counter the threat from terrorism, but the public can also play a big part as well.

"I would urge all Londoners - particularly as we now enter the festive season - to be vigilant when they are out and about in the capital over the coming days and weeks."

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The senior officer added that the Met was "very concerned about the increasing numbers of young people we're seeing feature in our investigations".

The arrested teenager was held on suspicion of disseminating of terrorist publications, arranging the availability of money or other property for the purposes of terrorism and "possessing a document likely to be useful to a person committing or preparing an act of terrorism".

The Met added that the arrest was not linked to the Israel-Hamas war.