Police had "no choice" but to raid a house in east London after being told a chemical device might be found there, a senior Met officer has said.
Abul Koyair's lawyer said no specific allegations had yet been put
Assistant Commissioner Andy Hayman said they received "specific intelligence", although nothing has yet been found.
Muslim Council of Britain leader Dr Muhammad Abdul Bari said police could lose the trust of Forest Gate residents if the situation was not clarified.
Two men were arrested - one of whom was shot and injured - after Friday's raid.
Mohammed Abdulkahar, 23, was treated in hospital for a wounded shoulder and then transferred to Paddington Green high security police station.
He was detained along with his brother, 20-year-old Abul Koyair, on suspicion of being involved in a terrorist plot - which both men have denied.
Police said the search of the terraced house in Lansdown Road could take until the end of the week.
Mr Hayman, head of the Met's Specialist Operations, said police had not yet found what they were looking for, but documents and computers had been taken away for analysis.
He refused to go into details about the information police received prior to the raid.
"We were left with no choice but to act upon that intelligence. Public safety was our top priority," he said.
'Anger and confusion'
Dr Bari, who was recently elected as head of the MCB, visited Forest Gate to listen to the "evident concerns" of Muslims in the area.
He said this was a "crucial time" for the Muslim community.
"The danger is the trust between the community and the police may be broken. The community feels very vulnerable."
He said the police needed to speed up their search because "three or four days' frustration, confusion and anger in the community is not good".
Mr Abdulkahar's solicitor, Kate Roxburgh, said detectives conducted a "preliminary interview" with her client on Monday evening and she expected more questioning on Tuesday.
About 250 officers took part in the raid on the terraced house
Earlier, she said he was "very coherent" and "very clear what happened", adding that "there was no struggle" with armed officers.
"He was coming down a flight of stairs, his brother was behind him and above him on the stairs. He was shot from in front by an officer at close range," she said.
The Metropolitan Police have never said a warning was given - an official statement said only that a 23-year-old man had received a gunshot wound.
Circumstances of shooting
A Scotland Yard spokeswoman said it was inappropriate for them to comment while an Independent Police Complaints Commission (IPCC) investigation into the incident was under way.
The IPCC said its investigation was focused "on the circumstances of the discharge of the police firearm".
It does not yet have accounts from all who witnessed the shooting.
Met detectives have permission to hold both men until Wednesday.
Mr Koyair's solicitor, Julian Young, said his client had already been questioned three times, but no specific allegation had been put to him.