Officers stormed the homes of a 17-year-old boy from London, a 21-year-old man from southwestern town of Bath and an 18-year-old man from Portsmouth early on Thursday morning as part of pre-planned raids by the North East Counter Terrorism Unit.
The 21-year-old was arrested on suspicion of possessing material useful to someone preparing an act of terrorism and conspiracy to inspire racial or religious hatred.
The 17-year-old was arrested on suspicion of encouraging terrorism, dissemination of terrorist publications, and conspiracy to inspire racial or religious hatred.
The 18-year-old was arrested on suspicion of encouraging terrorism and dissemination of terrorist publications.
Britain's counter-terrorism chiefs have repeatedly warned against the rising threat of far-right terrorism activity in the country.
Latest UK Home Office figures released in September indicated a growing threat from far-right extremism in the country, as a total of 351 arrests were made over the past year until June 2018 where terrorism-related activity was suspected, with 133 of them white and 129 recorded as Asian ethnic appearance.
"This was the first time, since the year ending June 2005, that the proportion of white people arrested has exceeded the proportion of Asian people arrested," a Home Office statement had noted.