A youth football league in Pennsylvania was forced to cancel the remainder of its 50th anniversary season following a series of violent, anonymous threats. 

Mount Pleasant Area Junior Football League announced this week that the drastic action was taken after four bullet casings - bearing the names of league officials - were found near a playing field.

At this point, police have no suspects, one of the team's coaches told Greta Van Susteren Thursday.

Chad Secosky, coach of the Norvelt Colts, said the bullets were found after threatening letters had already been sent to a league official.

Secosky said the threats began about six weeks ago and the situation has not improved.

Secosky believes the threats may be the work of parents who were involved in "incidents" at games earlier in the season.

He said the season got off to a great start, but then the threats started after about three or four weeks.

The cancellation affects five local squads, with each having three divisions ranging in age from 6 to 14.

He called it "unfathomable" that someone would ruin a football season for more than 200 players, along with the 100 or so cheerleaders. 

Watch the full interview above.

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