An army bomb disposal team was deployed to an area in Birmingham on Friday after police arrested five men on suspicion of preparing acts of terrorism.
The West Midlands Police Force said as a result of one of the arrests, an army bomb disposal team had been called in as a precautionary measure to the Lee Bank area.
The Fire Brigade said it had been assisting the police with the operation.
Police said two men aged 32 and 37 were arrested in the Stoke area of Staffordshire while three others, aged 18, 24 and 28 were arrested in Birmingham, Britain's second-biggest city.
"Police are searching a number of properties in the Stoke and Birmingham areas as part of the investigation; these searches are ongoing," they said in a statement.
"The arrests were intelligence-led and part of an ongoing investigation."
Britain is on its second-highest alert level of "severe", meaning an attack is considered highly likely.
As a result of one of the arrests the Army Bomb Disposal Team called in as a precautionary measure to Florence St. pic.twitter.com/ThJ6JvQMfy
— Birmingham Updates (@BhamUpdates) August 26, 2016