Ten former players have filed a class action lawsuit against the National Hockey League over injuries caused by concussions sustained during their professional careers.

The lawsuit, filed  in federal court in Washington D.C., comes six months after another civil action in May accused the NHL of failing to warn former player/enforcer Derek Boogard about the long-term health risks of head injuries. The ten named plaintiffs, including former Toronto Maple Leaf Gary Leeman, filed suit on behalf of themselves and all former players who retired on or before February 14, 2013, and have suffered concussion and related injuries as a result of playing in the NHL.

The plaintiffs allege the NHL took insufficient action to protect its players from unnecessary harm.

This inaction, they argue, occurred although the league knew or should have known of scientific evidence showing that players who sustain repeated head injuries are at a greater risk for disabilities during and after their hockey careers.

The lawsuit contends that because the NHL sets the league’s rules and regulations, it influences the risks to which players are exposed. As a result, the suit asserts, the NHL unilaterally assumed a duty to act in the best interests of the health and safety of the players and to provide truthful information regarding risks to their health. According to the complaint, “The NHL’s active and purposeful concealment of the severe risks of brain injuries exposed players to unnecessary dangers they could have avoided had the NHL provided them with truthful and accurate information and taken appropriate action to prevent needless harm.”

The complaint further states that because of the NHL’s failure to warn, “many of the players, including plaintiffs, sustained repetitive brain injuries while in the NHL and now suffer from latent or manifest neurodegenerative disorders and diseases, all of which, in whole or in part were caused by the NHL’s acts and/or omissions.”

The complaint also accuses the NHL of “promoting a culture of violence” that lauds players for their fighting skills.This culture, the players argue, continues to contribute to injuries today, as the league has refused to ban fighting and body-checking and has permitted the use of “enforcers,” players whose main job is to fight or body-check opponents.

As increasing attention is being paid to head injuries sustained in sports, this lawsuit comes just three months after the NFL faced a similar suit over its handling of concussions. In August, the NFL reached a $765-million settlement with thousands of formers players over the long-term effects of head trauma suffered during their careers. That agreement included compensation for cognitive injuries, the funding of medical exams for retirees, a research program and the payment of attorney’s fees.

The former NHL players are seeking more than $5 million in damages, an NHL-sponsored medical monitoring program for the players’ brain trauma or injuries, and attorney’s fees and costs.  According to initial media report, the NHL intends to vigorously defend this action and refute its claims.