Action News has learned a student was stabbed with a can opener that was brought into the school.
CHESTER, Pennsylvania (WPVI) -- A student was stabbed Thursday morning during an altercation at a high school in Chester, Pennsylvania.
It happened around 10:30 a.m. as some 250 students gathered in the cafeteria for first-period lunch.
Action News has learned a 17-year-old student was stabbed with a can opener that was brought into the school.
The injured student suffered a 4-inch laceration to the arm and three students, an 18-year-old and two 17-year-olds, were detained for questioning.
The injured student was taken to an area hospital.
The school does have metal detectors and officials said the can opener was brought from home. There is now an investigation as to how the weapon got through.
A school district official told Action News every student has to walk through the metal detectors.
Police said the 18-year-old student was charged with disorderly conduct. Charges for the 17-year-olds are being reviewed by the district attorney's office.
The school was on lockdown for a short period.
"We did take extreme measures to do a threat analysis, and unlocked the school as soon as that was conducted," said Chester Upland School District Receiver Nafis J. Nichols.
And despite the Chester Police Department being understaffed by about 20%, Police Commissioner Steven Gretsky said resources will be used to keep kids safe.
A school resource officer was in the area when the incident happened.
"This police department is here. I am from the city of Chester, I love the city, the kids, the people. We are here to protect and serve and that's what we will continue to do," Gretsky said.
School officials also say more metal detectors and X-ray machines are being delivered at the end of the month.