SEAFORD  — Seaford Police are investigating an incident where an unknown suspect, who was not on school property, reportedly displayed what appeared to be a handgun to a student Tuesday, authorities said.

According to spokesperson Deputy Chief Michael Rapa, the student was on the playground of the Cross Christian Academy at the time. One student was struck by a rock thrown by the suspect or an accomplice, police said.

All students on the playground entered the school building, which was then placed on lockdown, police said.

Seaford Police, assisted by Delaware State Police Troop 5 and Aviation, searched the area for the suspects with negative results, Deputy Chief Rapa said.

Authorities said the suspects are described as a tall Asian male wearing an Anime T-shirt and a Black male wearing a red and black shirt. One of the suspects was wearing a camo backpack, which is where the possible firearm was concealed, police said.

Officers are remaining on scene until all students are picked up, police said.

Deputy Chief Rapa asked that anyone who has information on the incident call the Seaford Police Department at 302-629-6645.