LONDON (Reuters) - Three British right-wing extremists were convicted on Wednesday of planning to carry out a terrorist attack at mosques or synagogues as part of a "race war", British police said.

Brogan Stewart and Marco Pitzettu, both 25, and Christopher Ringrose, 34, were preparing an act of terrorism when they were arrested in February 2024, prosecutors said at the start of their trial in March.

The trio were also each charged with two counts of collecting information which may be useful to someone preparing an act of terrorism, while Ringrose was charged with manufacturing a component for a 3D-printed FGC9 firearm.

They pleaded not guilty but jurors at Sheffield Crown Court convicted them of all charges on Wednesday. They will be sentenced on July 17.

"Stewart, Pitzettu, and Ringrose have today been rightfully convicted of multiple terrorism offences," Detective Chief Superintendent James Dunkerley, Head of Counter Terrorism Policing North East, said in a statement.

"They were a group that espoused vile racist views and advocated for violence, all to support their extreme right-wing mindset.

"Some of their defence in court was that it was all fantasy or just part of harmless chat, however all three took real world steps to plan and prepare for carrying out an attack on innocent citizens."

Prosecutor Jonathan Sandiford had told jurors that the three defendants expressed admiration for Adolf Hitler and perpetrators of notorious terrorist attacks, as well as hatred for non-white people, especially Muslims and immigrants.

"It was their belief that there must soon come a time when there would be a race war between the white and other races," Sandiford said.

Among hundreds of messages sent by the trio, including in a Telegram group called "Einsatz 14", the defendants discussed executing then prime minister Rishi Sunak and torturing imams.

(Reporting by Sam Tobin; Editing by Alexandra Hudson)