A controlled explosion has been carried out following the terror raids in Sheffield and Chesterfield earlier this week.
The Army Bomb Disposal Unit was yesterday brought in to carry out the explosion to safely dispose of material found at a flat above the Mermaid Traditional Fish Bar in Chesterfield.
The North East Counter Terrorism Unit said the blast took place at a safe location nearby and nobody was evacuated.
Superintendent Michelle Shooter said: "I would like to thank the local residents and businesses for their continued patience and understanding whilst the detailed search of the premises continues.
"Public safety is our priority and we understand events like this can be concerning. Our message remains for local people to remain alert but not alarmed."
A cordon yesterday remained in place around the flat in Chesterfield.
Officers arrested four people on Tuesday after raiding the property in Chesterfield and four others in Sheffield, including Fatima Community Centre in Burngreave.
Four men, aged 22, 31, 36 and 41, were arrested on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
All four remain in custody, and police have been given until Christmas Day to decide whether to charge or release the suspects, or to apply for more time to quiz them.