A second man has been arrested as part of an investigation in London by counter-terrorism officers.
The Metropolitan Police's counter-terrorism command detained the 40-year-old man in south-east London on Saturday.
He was held on suspicion of "being concerned in funding arrangements for the purposes of terrorism", Scotland Yard said, and is being questioned under the Police and Criminal Evidence Act.
It comes after police arrested a 30-year-old man on Wednesday on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
He was detained under the Terrorism Act 2000 and is being held at a south London police station.
Inquiries are ongoing, the Met said, and searches at a residential address in north London have concluded.
