A bank security guard shot an armed robber four times in thwarting the holdup of a Chase branch in Franklin Square Thursday evening, Nassau police said.

The suspect announced the robbery about 5:37 p.m. at the Franklin Avenue branch and pointed a semi-automatic handgun at two security guards, Assistant Chief Neil Delargy said at an 8 p.m. news conference at the scene.

“One security guard unholstered his weapon and fired approximately four times, striking that male subject four times,” Delargy said.

VideoPolice: Security guard shoots suspect during bank robberyDataGun crime numbersPhotosRecent LI mug shots

Police did not identify the suspect, but said he was hit on his extremities and taken to a hospital to be treated. No information about his condition was available.

Delargy said the security guard is a retired member of law enforcement, but would not elaborate.

No one else was injured, police said.

advertisement | advertise on newsday

Employees of stores in the strip shopping center locked their doors, keeping themselves and their customers inside.

A clerk at the CVS pharmacy next door said he called 911 when a customer ran from the bank saying someone had been shot and police arrived within three minutes.

“We closed the store as soon as we heard it,” said the clerk, who declined to give his name. “She said she saw a person down and bleeding. That’s when I called 911 and handed her the phone.”

There were about 12 customers at the store at the time, he said.

“We didn’t know what was going on,” the CVS clerk said. “People wanted to get out and leave and get out of the area. We didn’t know if a perpetrator was shot. We didn’t know if a customer was shot. We didn’t know if a bank employee was shot.

“Gunshots — you never know who’s going to be around or if he’s got a partner or what’s going down.”

A manager at Starbucks, right next to Chase, said he also locked the store’s doors.

A detective could be seen inside the ATM vestibule Thursday night holding up what appeared to be a blood-stained, white towel.

The shooting comes on the same day two Queens men were arraigned in Suffolk on bank robbery charges after leading several police agencies on a cross-county pursuit Wednesday that ended when their vehicle crashed into a Nassau police cruiser in Woodbury.