- Prosecutors say the three suspects were inspired by a decree from ISIS spokesman
- All have pleaded not guilty to terrorism charges
- Prosecutors say the men were planning an attack with knives and had bought a hunting knife online
Haseeb Hamayoon, 28, and cousins Nadir Ali Syed, 22, and Yousaf Shah Syed, 20, have all pleaded not guilty.
Prosecutors say the three were inspired by a fatwa, or decree, issued by ISIS spokesman Abu Mohammed al-Adnani, a document described as "truly chilling" by Max Hill, the lawyer for the UK's Crown Prosecution Service.
Hill told jurors the 11-page fatwa was aimed at Muslims throughout the world and encouraged acts of terrorism and murder, justifying the killing of police and servicemen.
He said the fatwa instructed followers to "Rig the road with explosives for them. Attack their bases. Raid their homes. Cut off their heads. ... Hunt them wherever they may be. ... Remove their families from their homes and thereafter blow up their homes."
Hill told the court the three men had been in constant contact by telephone messaging apps like WhatsApp and Telegram, sharing images and messages in the months running up to their arrest in November of last year.
Jurors were shown images that Hill said were found by police on Nadir Syed's mobile phone, showing Michael Adebolajo
, the murderer of British serviceman Lee Rigby, with the word "Mujahid."
They also saw images of ISIS beheadings and attacks that prosecutors said were on the suspects' phones.
The prosecution said the men purchased a menacing "Rambo First Blood II" hunting knife online.
The three men are each charged with one count of terrorism, a plot of "researching, planning and sourcing of weapons and equipment with a view to committing acts against persons in the UK using knives" between September 20 and November 7, 2014.
Hamayoon was in court dressed in a suit and the Syed cousins sat together in the dock wearing purple sweatshirts and skullcaps.
The trial continues.