The son of a one-time local leader in the Sinn Fein party was charged in Northern Ireland on Friday with possessing explosives, ammunition and other illegal equipment while allegedly planning dissident Irish Republican Army attacks.

Police arrested Turlough McAllister, 33, on Sunday at an apartment in the central square of Crossmaglen, the main Northern Ireland town in South Armagh, a border region long dubbed “bandit country” because of its reputation as an IRA power base.

Authorities said they found explosives, ammunition, a scanner used for monitoring police communications and a weapons manual.

McAllister’s arrest came the day after police discovered a 100-pound bomb hidden in a roadside hedge in the South Armagh village of Jonesborough. The explosives were packed inside a beer keg.

After four days’ interrogation, McAllister appeared under heavy police guard Friday in Newry Magistrates Court, but made no plea or bail application. He was ordered held pending his next court appearance Oct. 22.

He is the son of Jim McAllister, who for decades was the top official of the IRA-linked Sinn Fein in South Armagh. The elder McAllister quit the party several years ago to protest its decision to pursue IRA cease-fires and participate in a Northern Ireland government.

Jim McAllister, who attended Friday’s hearing but declined to comment, earlier accused members of the mainstream IRA of setting up his son and “trying to cast mud on my name.”

The father has been campaigning against IRA intimidation in South Armagh. He helped organize a pressure group seeking justice for the family of Paul Quinn, a 21-year-old truck driver allegedly beaten to death by current or former IRA members last year in an apparent dispute over fuel smuggling.