The accusations come one week after Eric Romig, 36, was arrested for having a sexual relationship with a 16-year-old.
That news was revealed as prosecutors asked a court to raise his bail on Thursday, concerned he might get out of jail and resume his relationship with that teen.
Prosecutors said they have now have four more girls who claim to have been approached by Romig for sexual encounters.
Some of the girls were students at the Faith Christian Academy in Sellersville at the time. Romig coached the girls' basketball team at the school between 2005 and 2010.
One of the girls claims she was sitting next to Romig on the team bus when he texted her with sexually suggestive messages.
The school has released a statement saying the allegations are very troubling and, "We encourage all former students who have any knowledge or information concerning this matter to contact the school and the authorities."
Meanwhile, the judge granted that request for a bail increase, raising it from 10% of $500,000 to $1 million cash.
Romig was arrested after the parents of that 16-year-old called police, saying the girl had been having sex with Romig, often at the home in Richland he shares with his wife and three children.
At the time of that incident, Romig had been the girls' softball coach at Pennridge High School.
Anyone with information should contact Bucks County detectives at 215-348-6354.