A grand jury has charged a man with threatening to harm liberal Sens. Bernie Sanders and Kamala Harris and protesters who took part in the March for Our Lives rally in support of stricter gun control.

According to an indictment filed in the US District Court for the District of Columbia, Nicholas Bukoski "threatened to assault and murder" Sanders and Harris and made a threat "to injure participants in the 'March for Our Lives' demonstration."

Sanders is an independent from Vermont and Harris is a Democrat from California. Both are influential figures in Democratic politics. The March for Our Lives was organized in the wake of a deadly shooting in February at Marjory Stoneman Douglas High School in Parkland, Florida.

A representative for Sanders declined to comment on the indictment. A representative for Harris did not immediately return a request for comment.

The indictment says Bukoski transmitted some kind of communication on or around March 24 with threats to harm Sanders, Harris and the protesters.

March 24 was the day the March for Our Lives took place.

Politico reported on Wednesday that the indictment had been sealed until last week when Bukoski was placed into federal custody.

An attorney for Bukoski did not immediately return a request for comment.