The men were suspected of “being concerned in the commission, preparation and instigation” of terrorism acts.

Four serving members of the British army were arrested under the Terrorism Act on suspicion of being members of a banned far-right group, British defense officials and police said on Tuesday.

The West Midlands Counterterrorism Unit said officers had arrested four people in central England alleged to be members of the neo-Nazi group National Action. The group is banned in the U.K., and an official list of banned groups describes it as “virulently racist, anti-Semitic and homophobic.”

The force said the men were suspected of “being concerned in the commission, preparation and instigation” of terrorism acts. They were detained as part of a “pre-planned and intelligence-led” operation and there was “no threat to the public’s safety.” No other details were immediately available.

Britain’s Ministry of Defense confirmed that the four men are serving members of the army.

“We can confirm that a number of serving members of the army have been arrested under the Terrorism Act for being associated with a proscribed far-right group,” the army said in a statement.

The men, aged 22 to 32, were held at a police station. Several properties were raided in connection with the arrests.

National Action was established in 2013 and has been linked to the murder of Labour lawmaker Jo Cox in 2016. The brutal murder, a week before Britain’s referendum on European Union membership, shocked the country.

The Home Office said that at the time, National Action posted tweets lauding Mair’s actions.

In a list of banned groups, the Home Office said the group frequently distributed “extremely violent imagery and language” on social media and aimed its propaganda at recruiting young people. It added that the group “seeks to divide society by implicitly endorsing violence against ethnic minorities and perceived ‘race traitors.’”

Membership or inviting support for National Action is a criminal offense that carries a sentence of up to 10 years.