OAKLAND (KPIX 5) – An Oakland imam is speaking out after police in Massachusetts shot and killed his brother, who was the focus of a federal terrorism investigation.

On Tuesday, Usaama Rahim was fatally shot by authorities near Boston. Sources told CBS News that officials has been tracking Rahim for the past 2-3 weeks.

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Sources said he was wanted for questioning about threats to law enforcement when officers approached him in a suburban Boston parking lot.

According to officers, they were forced to open fire when he lunged at them with a large knife, and refused repeated orders to drop it.

Investigators said Rahim had known extremist views and had been under 24-hour surveillance. They raided a home connected to the case Tuesday afternoon, but refused to say whether Rahim was connected with any known or suspected terror groups:

“I’m not gonna comment on what his plans were, weren’t, may have been, could have been,” said FBI Special Agent Vincent Lisi.

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Just a few hours ago, a second suspect was arrested in nearby Everett, Massachusetts.

Sources said he was also under surveillance, and may have been in contact with Rahim through social media.

Rahim’s brother, Ibrahim, is an imam at Lighthouse Mosque in Oakland. He tweeted on Tuesday “Pray4 my younger brother Usaama Rahim shot 3 X in his back by Boston Police then dying His last words I can’t breathe.”

Worshippers at the mosque told KPIX 5 that the terror allegations came as a shock to the community and are demanding answers about what happened.

“We feel that this is a tragedy, and we feel that it just shows kind of the intersectionality between two marginalized groups in America,” said Sundiata Rashid. “He represents another black man killed by law enforcement, and he represents a Muslim killed by law enforcement.”

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The imam has traveled to Boston to seek answers in his brother’s death.