Extra security patrolled the parking lots and other areas around Presbyterian Hospital on Thursday after two attacks on female employees in less than 20 hours.

By Thursday evening, no arrests had been made in the attacks, which happened Wednesday morning and evening.

Officials at Presbyterian Hospital, located in Charlotte’s Elizabeth neighborhood just southeast of uptown, said they had doubled security. Meanwhile, Charlotte-Mecklenburg police said they are reviewing surveillance footage.

Police said they don’t know whether Wednesday’s incidents are connected.

“However, at this time they are treating them as individual cases,” said Officer Jessica Lawrence, a police spokeswoman.

The first attack happened about 1:45 a.m. in a parking lot at the corner of Fifth Street and Hawthorne Lane, across from the hospital. A nurse who had finished her shift was approached by a man who stabbed her while grabbing her purse and tote bag, authorities said.

The nurse suffered shoulder injuries and has since been released from the hospital.

Then, about 6:20 p.m. Wednesday, a hospital secretary was assaulted in a parking garage where patients and employees park, officials said.

Police said the woman was pushed in a stairwell but did not elaborate on the incident.

Lt. Rich Austin said there were similarities – and differences – in the women’s descriptions of the suspects and that police are investigating possible motives in each case.

The suspect in the first attack was described as a black man who is about 25 years old and 6 feet tall with short hair, Austin said. The suspect in the second attack was described as a black man, age 20-30, who is between 5 feet 8 and 5 feet 10 with longer hair.

Elizabeth Steger, Presbyterian’s vice president of nursing, said she’d visited both victims since the attacks.

Steger said security officers were stationed at access points to the hospital’s campus following the incidents. Those officers are patrolling parking areas on foot and by car and bicycle. Employees have been encouraged to request escorts to their vehicles or to walk in groups.

Several police officers and security personnel were patrolling hospital grounds and near the parking deck Thursday morning. Employees who got off work about 7 a.m. appeared to be walking in groups to their cars.

Presbyterian Hospital is offering a $10,000 reward for any information leading to the arrest of the suspect or suspects. Anyone with information is asked to call Crime Stoppers at 704-334-1600.

The Observer’s Nancy Webb contributed.