Three members of a Kansas militia group were charged on Friday with plotting to bomb an apartment building filled with Somali immigrants in the western Kansas meatpacking town of Garden City.

Acting US attorney Tom Beall said Curtis Wayne Allen, Patrick Eugene Stein and Gavin Wayne Wright are members of a group calling itself the Kansas Security Force.

The arrests were the culmination of an eight-month FBI investigation that took agents “deep into a hidden culture of hatred and violence”, Beall said. The suspects conspired to detonate a bomb at a Garden City apartment complex where Somalis were among roughly 120 residents, he said.

The men, who were arrested in Liberal on Friday morning, performed surveillance of the apartment building and prepared a manifesto, Beall said. If convicted, the men could be sentenced to up to life in federal prison without parole.

Eric Jackson, special agent in charge of the Kansas City, Missouri, FBI field office, said the group has militia and sovereign citizen ties.

Garden City is home to a Tyson Foods beef slaughterhouse that has drawn a diverse immigrant population to the area.

The case is the latest involving militia groups in the state. Earlier this year, a planned armed protest outside a Wichita mosque prompted the Islamic Society of Wichita to cancel an appearance by a speaker whom protesters believed supported terrorism.