Top Republican Steve Scalise wounded in multiple shooting

A top US Republican and aides have been shot during baseball practice in Virginia, a congressman says.

Police in the upmarket Washington DC suburb of Alexandria said they were investigating a "multiple shooting" and a suspect was in custody.

Alabama lawmaker Mo Brooks told CNN House of Representatives Majority Whip Steve Scalise and aides were shot.

Police tweeted they were "investigating multiple shooting 400 block E Monroe St. Suspect believed in custody".

The lawmakers were practising for the annual congressional ballgame between Democrats and Republicans, which was scheduled to be played on Thursday at Nationals Park, home of Major League Baseball franchise the Washington Nationals.

An apparent eyewitness on Twitter, @ben_childers, said Wednesday morning's gunfire rang out at the YMCA baseball fields, by the Eugene Simpson Stadium Park.