Alleged gunman Omar Mateen called the Tsarnaev brothers his "homeboys" in a 911 call before the rampage at an Orlando nightclub, the special agent in charge of Boston's FBI said in a statement Monday, but "all evidence collected to date shows no connection between Mateen and the Tsarnaev brothers."
The FBI has previously said that Mateen called 911 three times during the attack on the Pulse gay nightclub. In one of the calls he pledged his allegiance to the Islamic State.
The attack early Sunday morning left 49 people dead and 53 others wounded -- the deadliest mass shooting in recent U.S. history.
The FBI Boston statement added that the agency currently has "no specific, credible threats to our area as a result of the Orlando attack."
Gov. Charlie Baker said Monday that extra security will remain in place throughout the state over the next few days. That includes at Logan Airport and on public transportation.
Baker said news of the shooting at the gay nightclub hit close to home. The governor said he spoke Sunday night with his brother Alex, who is gay.
The governor said Alex, and other gay friends he spoke with, told him they thought things were getting better, "and then we all discover that there are some people that just hate because of who we are. And there's no room for that, here in the commonwealth or anywhere in society."
Massachusetts Attorney General Maura Healey reacted to the shooting in Orlando by calling for the reinstatement of a federal assault weapons ban.
Healey told WBUR's Radio Boston on Monday that while the motives of the gunman can be debated, what can't be denied are the weapons used in the shooting.
"I am sick and tired of fighting about the Second Amendment," Healey said. "It is there, it stands, it's a right we must respect and do respect. But it is not a zero sum game. There is a role for public health, for public safety."
Among the victims of the Orlando attack were at least two people with Massachusetts ties: 37-year-old Kimberley "KJ" Morris and 23-year-old Stanley Almodovar III.
Morris was from western Massachusetts and worked as a bouncer at Pulse in Orlando.
Almodovar was originally from Springfield and was living in the Orlando area.
At least two vigils in the Boston area are planned Monday night to honor the Orlando victims: one at Boston City Hall Plaza at 6 p.m. and one at Cambridge City Hall at 5 p.m.
With reporting by WBUR's Steve Brown