British police have arrested seven more suspects in their latest anti-terrorist sweep.
Authorities say six men and one woman have been detained under the Terrorism Act.
The suspects were arrested in a series of pre-dawn police sweeps Thursday in the Scottish cities of Glasgow and Edinburgh, as well as in London and the northwest English city of Manchester.
Scottish police officers spearheaded the operation, with support from the anti-terrorist branch of London's Metropolitan Police Service.
A police spokesman says no dangerous substances have been found in the raids so far, but the search continues.
Britain has been on alert for potential terrorist attacks since the discovery of traces of deadly ricin toxin in a North London apartment a month ago. Police have made arrests in several European countries since that initial discovery.