WASHINGTON: Two men have been arrested and charged with plotting to attack a military centre for enlistees in Seattle with grenades and machine guns, the US Justice Department said on Thursday.

Abu Khalid Abdul-Latif, 33, of Seattle, and Walli Mujahidh, 32, of Los Angeles were arrested on Wednesday evening on a seven-count complaint accusing them of conspiracy to murder officers and employees of the United States, conspiracy to use grenades and other firearms offenses.

If convicted, the two could face up to life in prison.

An unidentified individual who had known Abdul-Latif for several years was approached by him in late May to participate in the plot and supply weapons, but instead the person went to the Seattle Police Department, authorities said.

The individual, who has a criminal record, became a paid confidential informant in an undercover operation to nab the two men, according to prosecutors.

Abdul-Latif mentioned the 2009 shooting rampage at Fort Hood, Texas, where an Army major is accused of killing 13 people, noting that “if one person could kill so many people, three attackers could kill many more,” the informant told authorities, according to the criminal complaint.

The planned attack was to retaliate for alleged crimes by US soldiers in Afghanistan, Abdul-Latif told the informant, according to an FBI affidavit. Video and audio recordings of some of the conversations and meetings were made during the undercover operation.

US authorities have been increasingly worried about militants inspired by al Qaeda leader Osama bin Laden launching attacks in the United States, particularly lone individuals or small groups that are particularly difficult to track.

“But for the courage of the cooperating witness, and the efforts of multiple agencies working long and intense hours, the subjects might have been able to carry out their brutal plan,” Laura Laughlin, the special agent in charge of the FBI's Seattle division, said in a statement.

Switched targets

The two men originally planned to attack the Joint Base Lewis-McChord in Washington state but then switched targets to the place where military enlistees are screened and processed, according to prosecutors.

Abdul-Latif developed an extensive plan of attack on the military centre, three miles south of downtown Seattle, and noted he wanted to attack people in the military, not civilians, the complaint said. He expressed little concern about dying in the planned assault, it added.

“Abdul-Latif explained that, in his view, murdering American soldiers was justifiable,” the affidavit said. The two were provided weapons that were brought by the informant but had been rendered inoperable by law enforcement authorities.

Abdul-Latif provided the informant with $800 in cash to help buy the weapons and arranged to buy a bus ticket for Mujahidh to travel from Los Angeles to Seattle to participate in the attack, prosecutors said.

After being arrested, Mujahidh waived his legal rights and told FBI agents that the plot was to prevent US military personnel from going to Islamic lands and killing Muslims, the affidavit said.

The two men appeared in a crowded Seattle federal court on Thursday afternoon to hear the charges against them. They are being held pending a detention hearing next Wednesday. A preliminary hearing on the charges has been set for July 7.