WASHINGTON -- Ten former National Hockey League players, including all-star defenceman Gary Leeman, claimed in a class-action lawsuit that the league hasn't done enough to protect players from concussions.

The lawsuit seeks damages and court-approved, NHL-sponsored medical monitoring for the players' brain trauma and/or injuries, which they blame on their NHL careers. It was filed in federal court in Washington on behalf of players who retired on or before February 14 of this year and have suffered such injuries.

The suit comes just three months after the National Football League agreed to pay US$765 million to settle lawsuits from thousands of former players who developed dementia or other concussion-related health problems -- and in an era when more attention is being paid to the damages of head injuries sustained in sports.

Among other things, the suit claims that:

-- The NHL knew or should have known about scientific evidence that players who sustain repeated head injuries are at greater risk for illnesses and disabilities both during their hockey careers and later in life.

-- Even after the NHL created a concussion program to study brain injuries affecting NHL players in 1997, the league took no action to reduce the number and severity of concussions during a study period from 1997 to 2004. "Plaintiffs relied on the NHL's silence to their detriment," the suit says.

-- The league didn't do anything to protect players from unnecessary harm until 2010, when it made it a penalty to target a player's head.

"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 lawsuit says.

Bill Daly, the league's deputy commissioner, issued a statement Monday.

"We are aware of the class-action lawsuit filed today in the United States District Court for the District of Columbia on behalf of a group of former NHL players. While the subject matter is very serious, we are completely satisfied with the responsible manner in which the league and the players' association have managed player safety over time, including with respect to head injuries and concussions," the statement said. "We intend to defend the case vigorously and have no further comment at this time."

The NHL didn't respond to AP's requests for comment, but earlier this year, NHL commissioner Gary Bettman told The Canadian Press the league had "taken tremendous strides and put a great deal of effort and time and money into dealing with the issue of player safety, in general, and concussions, specifically.

"We were the first sports league in '97 to have a joint working group to study concussions with the Players' Association and our trainers and our physicians. We were the first sports league to do baseline testing, we were the first sports league to have protocols for diagnosis and return-to-play decisions.

"This is something that we have always treated as important and will continue to treat as important," he added.

The suit argues that the league continues to contribute to injuries today, by refusing to ban fighting and body-checking, and by employing "enforcers" whose main job is to fight or violently body-check opponents. And the lawsuit accuses the league of promoting a "culture of violence," in which players are praised for their fighting and "head-hunting" skills.

Leeman, who played for the Toronto Maple Leafs, Calgary Flames, Montreal Canadians, Vancouver Canucks and St. Louis Blues from 1983-1996, suffered multiple concussions and sub-concussive impacts during his career, according to the lawsuit. Since his retirement, he's suffered from post-traumatic head syndrome, headaches, memory loss and dizziness, the lawsuit says.

In addition to Leeman, the other ex-players on the lawsuit are: Bradley Aitken (Pittsburgh Penguins, Edmonton Oilers); Darren Banks (Boston Bruins); Curt Bennett (Blues, New York Rangers and Atlanta Flames); Richard Dunn (Buffalo Sabres and Calgary Flames); Warren Holmes, (Los Angeles Kings); Robert Manno, (Canucks, Maple Leafs and Detroit Red Wings); Blair James Stewart (Red Wings, Washington Capitals and Quebec Nordiques); Morris Titanic, (Sabres); and Rick Vaive (Canucks, Maple Leafs, Sabres, and Chicago Blackhawks).

In a statement, Vaive said players "were kept in the dark about the risks of concussions and many of the former NHL players are now suffering from debilitating head injuries from their time in the league. Hopefully this lawsuit will shine a light on the problem and the players will get the help they deserve."