Police investigating an alleged kidnapping plot are to widen their search to another three properties.
Police have been combing 15 properties
Assistant Chief Constable David Shaw said six searches of premises in Birmingham had already been completed and another nine were continuing.
He said officers were due to begin interviewing the nine men arrested in raids across the city.
They are being held at a Coventry police station on suspicion of planning to kidnap and murder a Muslim soldier.
At an afternoon press conference, ACC Shaw told reporters the searches so far had yielded a "significant quantity of exhibits" but would give no further details.
It is known however that over the last two days cars and vans have been removed from streets, and computer equipment, books and video players have been taken from raided properties.
Addressing the communities where Wednesday's raids took place, he said he would try to keep any disruption caused by the searches to a minimum.
"Can I just assure everybody that we do these searches as quickly as possible - but we do need to balance the disruption we are causing you with doing a thorough, professional job," he said.
He added that he was also aware of "considerable bewilderment" about what had been alleged to have taken place.
"Despite certain labels given to those men by the media, what we are dealing with here in its purest sense is criminality," he said.
"My job is to continue to make sure I balance the needs of the public, the safety of the public, and the rights of the men who are in custody."
He stressed that the treatment of the nine suspects was being kept under scrutiny.
They were arrested under the Terrorism Act over what security sources say was a plan to film an execution-style murder of a British soldier and post it on the web.
Since then, forensic teams have been combing addresses in the Sparkhill, Alum Rock, Kingstanding and Edgbaston areas of the city.
On Thursday, a district judge granted police extra time to interview the suspects. They now have until 6 February.
Under new terror laws, police can apply in court for a series of extensions up to 28 days.
Meanwhile, religious leaders have urged Muslims to control their anger over the way the raids were conducted.
Chairman of Birmingham Central Mosque, Dr Mohammad Naseem, said Muslims felt "persecuted unjustly" by the government.
Police officers have been handing out leaflets aimed at reassuring local people.