20 injured in Pittsburgh-area high school stabbings, authorities say

• Suspect in custody, authorities say
• Stabbings happened at Franklin Regional Senior High School in Murrysville
• One student flown to hospital, emergency management spokesman says

At least 20 students were injured in Wednesday morning's stabbing incident at the Pittsburgh area's Franklin Regional Senior High School, said Dan Stevens, an emergency management agency spokesman.

Four were flown to hospitals by helicopter, he said.

A message on the Franklin Regional School District's website said all of its elementary schools were closed after the incident, and "the middle school and high school students are secure."

Earlier version, posted at 8:29 a.m. ET]

At least 8 stabbed at Pittsburgh-area high school, authorities say

(A suspect was in custody after eight students were stabbed Wednesday morning at western Pennsylvania's Franklin Regional Senior High School, authorities said.

One of the injured students was being flown to a local hospital, said Dan Stevens, an emergency management agency spokesman.

Information on what led to the stabbings and the conditions of the injured were not immediately released.

The school is in Murrysville, about 15 miles east of downtown Pittsburgh.

The school was releasing students to their parents after the incident, Stevens said.

CNN first learned of the stabbings on Twitter.