Three men have been found guilty of "infecting the young minds of children" by encouraging support for Islamic State.
Mohammed Istiak Alamgir, Yousaf Bashir and Rajib Khan gave speeches at a series of meetings in Luton during Ramadan last year, attended by up to 80 people including young children.
Khan was also convicted by a majority of nine jurors to one at the Old Bailey of arranging one of the meetings at a local church.
A major joint investigation between Bedfordshire Police and the Metropolitan Police - dubbed Operation Weedproof - saw an undercover officer infiltrate the group for 20 months.
The men were alleged to be supporters of the proscribed group al-Muhajiroun (ALM).
Commander Dean Haydon, head of Scotland Yard's Counter-Terrorism Command, said: "The biggest concern we had was with children present of a very young age, as people start growing up, particularly in Luton, we need to avoid individuals either travelling to Syria or becoming involved in extremist acts or even terrorist acts.
"What this group of people were doing was infecting the young minds of children."
Alamgir, 37, was found guilty of three counts of addressing meetings to encourage support for a proscribed organisation, namely IS, or to further its activities. A fourth count which the jury could not decide on will lie on file.
Bashir, 36, was found guilty by a majority of addressing a similar meeting on June 29.
Khan, 38, was convicted of arranging, managing or assisting in arranging a meeting to support IS on July 11, and addressing a similar meeting on July 11. They are all from Luton.
The defendants made no reaction as the verdicts were delivered after eight days of deliberations.
Sue Hemming, CPS Head of Counter Terrorism, said: "These men sought to divide our society with messages of hate and extremism and their desire for a role in conflict and conquest has only ended in a conviction.
"Knowingly encouraging people to join or support a proscribed organisation is a crime and will be prosecuted."
The jury of 10 was unable to reach verdicts on two co-defendants - Mohammed Choudry and Zaiur Rahman - who will face a retrial at the Old Bailey on November 14.
Rahman, 38, from Luton, faces three counts of arranging a meeting to support IS while Choudry, 23, from Maidenhead, Berkshire, is charged with a single count of encouraging support for IS.
Commander Dean Haydon, head of the Met Police Counter Terrorism Command, said: "These men were closely associated with Al-Muhajiroun, a dangerous group which has inspired and influenced numerous terrorists.
"Speeches like theirs inspire the terrorists of tomorrow and I am immensely pleased with the excellent work of my officers and Bedfordshire Police, which ensured the conviction of these men."
Assistant Chief Constable Jeff Hill, from the Eastern Counter Terrorism Intelligence Unit, said: "Luton is a fantastic town with great diversity and strong communities, however we are aware there are elements with extreme views who prey on the vulnerable.
"We simply will not tolerate those who spread fear and hate in our communities and will continue to target, arrest and disrupt those with extreme views."