(Reuters) - A Tennessee man was arrested on Wednesday for allegedly posting threats online to “shoot up” a facility run by Planned Parenthood in Washington D.C., the latest arrest in a nationwide law enforcement effort to thwart mass shootings.

Jacob Cooper, 20, was accused in federal court in Nashville, Tennessee, of violating a federal law against sending interstate threats with his posting about Planned Parenthood, the women’s healthcare and abortion provider.

According to prosecutors, Cooper left a comment on Aug. 13 on the meme-sharing website and app iFunny stating, in response to a post made by another user, “Make sure you tell them about how I plan to shoot up a planned parenthood facility in Washington D.C., on August 19th at 3pm.”

Cooper is at least the sixth person in the past month to be charged with threatening a mass shooting.

Gunmen in El Paso, Texas, and Dayton, Ohio, killed 31 people using semi-automatic rifles and high-volume magazines earlier this month.

Isaiah Gant, a public defender appointed to represent Cooper, declined to comment.

Cooper faces a maximum penalty of five years in prison if convicted, prosecutors said.

The arrest came amid a crackdown by U.S. law enforcement agencies on online threats to carry out mass shootings.

Police in Long Beach, California, south of Los Angeles, on Wednesday announced the arrest of a Marriott hotel chef accused of threatening to carry out a mass shooting at the hotel in a dispute with his employer.

Long Beach Police Chief Robert Luna told reporters at a news conference the suspect, Rodolfo Montoya, 37, was taken into custody on Tuesday at his home in nearby Huntington Beach, where police said they found an arsenal of weapons, ammunition and high-capacity ammo magazines.