WASHINGTON – A possible terrorist plot against military personnel at Fort Hood in Texas was disrupted with the arrest of an Army private who had purchased ammunition and bomb-making materials in preparation for such an attack, law enforcement officials said Thursday.

Pfc. Naser Jason Abdo, a 21-year-old Texas native who had successfully argued that he was a conscientious objector whose Muslim faith would not allow him to deploy to Afghanistan, was arrested at a motel Wednesday by Killeen police after his purchase of gunpowder at a local gun store aroused employees’ suspicion. Abdo, who had been charged earlier this year with possession of child pornography, had been absent without leave since early July.

Authorities suspect that Abdo, who was assigned to the 101st Airborne Division at Fort Campbell in Kentucky, was planning to construct bombs and detonate them at a restaurant popular with Fort Hood personnel, according to a U.S. official who has been briefed on the case. Abdo intended to gun down survivors after the bombs went off, the official said.

“Military personnel were targeted,” Killeen Police Chief Dennis Baldwin said at a news conference. After interviewing Abdo, authorities believe he was acting alone, Baldwin said. “I would classify it as a terror plot,” he said.

The U.S. official said Abdo chose the Fort Hood area for the planned attack because the base was the scene of a 2009 attack by Maj. Nidal Malik Hasan, an Army psychiatrist, who went on a shooting rampage that killed 13 people and wounded 32 at a medical facility.

The Killeen gun store visited by Abdo was the same one where Hasan bought weapons and ammunition, authorities said. Hasan is awaiting court martial on 13 counts of premeditated murder and 32 counts of attempted premeditated murder, charges that could bring the death penalty.

In May, the Army accepted Abdo’s claim to be a conscientious objector. But a week later, the Army put the resulting discharge on hold after charging him with possession of child pornography and beginning court martial proceedings against him.

Abdo has denied the charges and claims them simply to be retaliation for refusing to go to Afghanistan.

He went AWOL from Fort Campbell on July 4 and had not been heard from until his arrest at the motel, the official said.