All eyes were on the Reading Intermediate High School -- the Citadel -- on Tuesday as students returned to class after the Easter break.

The increased attention comes after a series of fights, involving up to 100 students, erupted throughout the city last Wednesday.

The long weekend for students, however, was exactly what was hampering the investigation, authorities said, because officers inside the school didn't have access to students to obtain vital information.

"Our officers usually hear rumors going on in the schools, you know, people come in and report what they saw the day before. But this fight occurred right before the break for Easter," said Sgt. John Solecki, Reading Police Dept., in a interview with 69 News last week.

"So, we haven't really gained any intelligence from the school buildings that we usually get after an incident like this occurs," said Solecki.

While police carried out their investigation, some parents and students approached the first day back to class with caution.

"I'm very much concerned," said Carmen Reynoso, who has several kids who attend the Citadel. "It's very unpredictable, and you see the kids coming out and going to the corners to fight."

During last week's fights, police said students showed up with bats, two by fours, and even what appeared to be a table leg.

Cell phone video of the fights were posted on Facebook and YouTube, authorities said.

Some of the images still haunted some students Tuesday as they tried to concentrate on their studies.

"It's scary," said Jenessa Rivera, student, "because I don't know if it would happen to me."

Now the big question is who are the kids in this video, and what could have caused them to attack each other so viciously.

Police said the students that showed up to the fight with weapons will face charges.

Until that happens, parents like Carmen Reynoso said they will make it a priority to pick up her children, personally.

"Every day," Reynoso said. "Drop them off and pick them up."

The mayor of Reading said he has plans to speak with Reading School District Superintendent Carlinda Purcell to figure out what caused these fights.