Testimony by a key government witness in Minnesota's ISIL recruitment trial had to be paused Friday afternoon after a confrontation erupted in the audience, prompting the trial judge to remove several people from the courtroom.

As Abdullahi Yusuf testified about his relationship with the three defendants, an audience member made comments to Yusuf's mother, seated nearby, and court security ordered them to leave. Yusuf's mother was later allowed back inside.

A short time later, the district's chief judge issued an order barring Khadar Ali Omar, brother of defendant Guled Omar, from the courthouse. Khadar Omar had been stopped Thursday while trying to bring a 6-inch pair of scissors into the building and had also taken photos of the building's public elevators.

Yusuf, 20, is one of the government's three star witnesses in the trial of Abdirahman Daud, 22; Mohamed Farah, 22, and Omar, 21, in U.S. District Court in Minneapolis. The three are accused of conspiring to provide material support to the Islamic State in Iraq and the Levant (ISIL) and to commit murder abroad for the terrorist group.

Along with Yusuf, they were among 16 mug shots on a chart given to jurors, showing young Minnesotans who since 2014 have tried, some successfully and some not, to fight for ISIL in Syria.

Omar, who Yusuf said was appointed as "emir," or leader, of the group, took notes throughout Yusuf's testimony and at one point tried to lock eyes with him. He dropped his jaw as Yusuf described a pivotal spring 2014 meeting at a Bloomington mosque that went into the early morning hours. After playing basketball, Yusuf said the friends spent hours watching propaganda videos about atrocities committed by the Syrian government — which Yusuf said first caught his attention when he was assigned to write a high school history report on the country.

"I was recruited that night," Yusuf said.

"And who recruited you?" asked Assistant U.S. Attorney John Docherty.

"Guled Omar."

Yusuf, who was nicknamed "Bones" for his lanky figure, leaned in toward a microphone during his testimony, which took up most of Friday's proceedings.

Yusuf's best friend, Hanad Mohallim, then 18, was reportedly killed fighting for ISIL in 2014. For a time, Yusuf said, Mohallim had kept in touch through encrypted social media accounts and had said he would put Yusuf in contact with ISIL fighters. But it was an ultimatum from Omar, Yusuf said, that helped shift the group's focus on firm plans to leave the country.

"He told me we were about to go on a long, hard journey and if I turned around and walked away there would be no hard feelings," said Yusuf, who told Omar he wanted in on the group's plans.

Yusuf carefully walked jurors through the names and corresponding chart numbers of friends involved in various meetings, ranging from paintball sessions to shopping trips for clothes to take abroad. The name Abdi Nur surfaced repeatedly. Nur, Yusuf said, linked the friends up with a Yahoo e-mail account used to communicate with ISIL fighters by saving but not sending messages in a "drafts" folder.

Yusuf also said Daud shared phone numbers of ISIL contacts who could get him from Turkey to Syria. Farah helped him prepare to apply for an expedited passport, Yusuf said, and Omar gave him the $200 for a down payment on the application.

But, as a passport specialist testified earlier this week, Yusuf became rattled while being interviewed about his plans to travel to Turkey, landing him on federal authorities' radar. The specialist said Wednesday that Yusuf appeared nervous and could barely name a tourist location in Istanbul, where he said he was planning to vacation.

The morning of Yusuf's ill-fated attempt to fly out of Minnesota in late May 2014, as his father dropped him off at his high school, Yusuf said he reflected on the likelihood that they'd never see each other again. "I tried to talk about old memories," Yusuf said, and gave his father an out-of-character hug.

FBI special agent John Thomas, one of two agents assisting the prosecution at trial, stopped him from boarding his flight. Back home and aware he was under watch, Yusuf said he limited contact with the group's members for fear of getting them involved in the investigation. He tweeted "The weather is hot today" to let others know of his failed attempt.

Later, after Yusuf received a text from his attorney that he would soon be arrested, everyone in the group but Omar told him he should leave the country, he said. So Yusuf started plotting again that fall to leave with Daud, Farah and Farah's younger brother, Adnan. Daud helped urge Yusuf on, he said.

"He said how can I fool myself to think I can live here," Yusuf said. "The West is the enemy and they would arrest me. I had to leave."

Yusuf's testimony is expected to resume on Monday with further questioning from Docherty.

Stephen Montemayor • 612-673-1755

Twitter: @smontemayor