Mohamed Abdullahi Hassan, the former Minneapolis high school student-turned-jihadi recruiter, has been tied to at least two more terror plots within the United States.

Hassan, who goes by Mujahid Miski online, traded tweets with a Rhode Island man now facing federal terrorism charges for his role in an alleged plot to kill police officers, according to security analysts. Hassan is also thought to have been in contact with a New York City college student who federal investigators say was intent on bombing local landmarks. Both suspected plots were foiled by authorities.

Earlier this year, Hassan was accused of influencing a gunman who tried to ambush a cartoon contest in Texas that was to feature depictions of the prophet Mohammed. The gunman and an accomplice were killed.

In the New York case, Hassan reportedly contacted Munther Omar Saleh, a college student, who on June 13 was arrested after he and an unidentified cohort ran toward an undercover law enforcement car that was tailing them near the Whitestone Bridge in New York City, according to security analysts. Authorities say that the two men were plotting to plant bombs at famous sites across the city.

Hassan also reportedly communicated online with Nicholas Rovinski in the months before the Rhode Island man was arrested for his role in an alleged plot to kill police officers and behead a blogger, analysts say.

Sometime after Rovinski's arrest, Hassan stopped tweeting, leaving security analysts and loyalists of the Islamic State of Iraq and the Levant (ISIL) wondering the same thing: Where is he?

"I think Miski [Hassan] was obviously Exhibit A of these guys that would misuse Twitter and would keep coming back and keep resurfacing," said Mark D. Wallace, chief executive of Counter Extremism Project, a group which tracks the funding of jihadi groups like ISIL. His disappearance from Twitter is "effectively taking a weapon off the field for extremists because he'd effectively weaponized Twitter."

Wallace said that Hassan has "gone dark" before, abandoning Twitter for long stretches, and that any speculation about his death or capture is premature.

Still, a tweet posted earlier this week on a since-deleted account belonging to an ISIL loyalist appeared to shed light on Hassan. The tweet read: "Still cant get access to other friends heard some of them got martyrdom & some become prisoners. #MujahidMiski #AbuMohammad #Mutawakil."

Few people outside intelligence circles had heard of Hassan before May, when he was identified as a strong influence on Elton Simpson, a Phoenix man who, along with a second gunman, opened fire outside the cartoon contest in the Dallas suburb of Garland, Texas.

A series of tweets between Hassan and Simpson, over the span of several months, illuminated the challenges facing U.S. intelligence officials seeking to keep up with jihadi recruiters online, an exercise that some analysts likened to a game of Whac-A-Mole.

Twitter has suspended thousands of accounts affiliated with extremist groups, only to have the same users start a new profile under a different handle.

Hassan, who has been connected to a group of Twin Cities men recently accused of trying to join ISIL, was among the second wave of Twin Cities men of East African descent who left the country in 2008 to join the Islamic extremist group Al-Shabab.

He was indicted the following year for conspiracy to support terrorism and added to the FBI's list of most-wanted terrorists.

Speaking before the House subcommittee on terrorism earlier this year, Wallace referred to Hassan as "not only one of the most influential jihadis using Twitter to spread propaganda and recruit, he has also been responsible for tweeting some of the most heinous, violent content we've seen."

Before going silent on Twitter two months ago, Hassan boasted that his account had been suspended more than 30 times.

Ben Petok, a spokesman for the U.S. attorney's office, declined to comment Thursday on Hassan's activities.

When Hassan left Minneapolis he was in his senior year at Roosevelt High School. After boarding a flight from Minneapolis to Charlotte, N.C., he eventually made his way to Somalia, where he joined other fighters with the State Department-designated terrorist group, court documents say.

Hassan was thought to have been killed in Mogadishu, according to a 2009 House report.

Not all security experts are convinced of Hassan's new role in ISIL's propaganda machine.

"I think it's similar to the Lakers: next man up. You know, if Kobe [Bryant] goes down, somebody else will step up," said Colin Clarke, a political scientist at the RAND Corp., a nonprofit research group that focuses on security issues.

"You know they may not be as talented, but they will step in for him,'' Clarke added. "I think that's one of the things that makes (ISIL) so successful: because it's got probably hundreds of Miskis."

Libor Jany • 612-673-4064 Twitter:@StribJany