Gwangju Bukbu Police Station said it received a report at 11:50 a.m. on July 4 about an online post claiming a bomb had been planted at Gwangju Jeil High School.
Police and fire authorities are searching the school premises but no explosive devices have been found so far.
The threatening post also claimed that "the future of Pai Chai High School has been violated," apparently referring to remarks made by Pai Chai players toward the Gwangju Jeil dugout during a recent tournament.
The Korea Baseball Softball Association imposed a six-month suspension on Pai Chai's baseball team. Pai Chai High School plans to hold an official apology event on Monday, while its alumni association has called for leniency.
