A trooper shot and wounded a man armed with a shotgun at a busy Pennsylvania Walmart after the man robbed the pharmacy for prescription drugs, state police said.

State police received a call Thursday night from the Walmart in Shrewsbury, saying the store about 40 miles south of the state capitol of Harrisburg had been robbed.

A trooper who was in the area responded and spotted the suspect as he was leaving the store.

Authorities said the trooper told the man to drop the shotgun. That's when the man raised his weapon.

"The trooper was able to simultaneously push the shotgun barrel away while firing one round. The subject also fired a round as well," Trooper Rob Hicks said.

The trooper's bullet struck the man in the chest.

One witness, Roni Zentz, told the York Daily Record that she was sitting near the pharmacy when she saw a man yelling at pharmacy employees and cradling what appeared to be a shotgun in a black garbage bag.

She said she told someone to call security, and then heard two gunshots.

"I ran through the garden section," Zentz told the newspaper.

She said the man was shot near the doorway.

State police said he was taken to hospital. His condition wasn't immediately available.

There were no other injuries reported.

"It's a very scary situation for everybody involved," said Hicks. "I mean our trooper, the people who were in there shopping, the employees.  A very nerve-racking situation. Thank God nobody else was hurt."

The trooper is on administrative leave pending the results of an investigation into the shooting.

Click for more from Fox 43.