A U.S.-trained Pakistani scientist accused of shooting at U.S. authorities trying to interview her in Afghanistan yelled "I'm going to kill all you Americans" during the confrontation, a witness testified Wednesday.

The witness spoke after Aafia Siddiqui returned to court, promising to behave herself a day after getting kicked out of her own trial after calling another witness a liar.

Siddiqui told Judge Richard Berman she would be quiet on even though she might disagree with testimony. The judge told her he wanted no more outbursts.

The 37-year-old Siddiqui, a frail-looking neuroscience specialist who trained at the Massachusetts Institute of Technology and Brandeis University, was charged with attempted murder after her arrest in Afghanistan in July 2008. Authorities say she was caught carrying notes on bomb-making and a list of New York landmarks.

Prosecutors allege Siddiqui, while detained in a dingy room full of Afghan and U.S. personnel, grabbed an unattended rifle and shot at the others before a soldier returned fire. Besides the defendant, who suffered a gunshot wound to the stomach, no one was seriously injured.

She has vehemently denied any wrongdoing and is not facing terrorism charges.

FBI agent John Jefferson testified Wednesday that when the 2008 fracas erupted, he heard Siddiqui yelling, "I'm going to kill all you Americans." He said he was surprised it was in "perfect English."

Witnesses said once the shooting stopped, Afghan security personnel — some wielding rifles and looking angry — began swarming as about 15 U.S. authorities tried to carry away a still-kicking Siddiqui on a stretcher outside the police station.

"We were pretty much in a standoff," Jefferson said. He said they pushed past the men and loaded Siddiqui onto a vehicle.

On Tuesday, testimony indicated that the gunfight created friction within the U.S. Army over how Siddiqui got her hands on a soldier's assault rifle.

U.S. Army Capt. Robert Snyder told the jury that the soldier, a chief warrant officer whose name was not released, created a deadly risk by not securing his weapon. He described seeing the soldier put down the rifle and turn away to shake hands with police before the gunfire erupted.

That same soldier was the one who ended the melee by shooting Siddiqui.

Snyder said he recoiled when another captain later approached him about awarding the soldier a medal for valor.

"I told the captain I would not support it — absolutely not," Snyder said.

One of Tuesday's outbursts followed Snyder's testimony that Afghan police discovered the notes in Siddiqui's purse mentioning a massive attack and listing landmarks such as the Empire State Building, the Statue of Liberty and Wall Street.

"I was never planning a bombing! You're lying!" the 37-year-old Siddiqui yelled as she was rushed out of court.