Senate Democrats will push for funding that would allow the FBI to add nearly 400 new positions to fight terrorism in the wake of the deadly attack at a gay nightclub in Orlando over the weekend.

Forty-nine people were killed and dozens more injured when a gunman opened fire early Sunday morning at the nightclub. Officials say they are investigating the shooting as a terrorist attack.

Maryland Sen. Barbara A. Mikulski and Florida Sen. Bill Nelson introduced legislation to allocate an additional $190 million to the FBI to strengthen counterterrorism efforts.

“We need to get the FBI the tools it needs to keep up with those trying to recruit Americans to extremist ideologies or spread messages of hate to inspire others,” Mikulski said in a statement. “We also need our first responders on the front lines to be prepared to keep victims safe, get them out of danger, and get them the medical help if they need, should the unthinkable happen.”

Mikulski and Nelson offered their legislation as an amendment to the spending bill that funds the Justice Department, which was expected to be voted on the Senate floor. But a filibuster on gun control, led by Connecticut Democratic Sen. Christopher S. Murphy, stalled action on the bill.