More than 200 transit police officers in south-eastern Pennsylvania have walked out on strike, forcing authorities to use private security firms to patrol subways and stops in the Philadelphia area.

Members of the Fraternal Order of Transit Police, Local 30 division, were called off their jobs on Wednesday, just minutes after negotiations with transit organization SEPTA broke down, NBC10 Philadelphia reported.

The station reported that the union has been in talks with SEPTA management from April last year and officers had been working since then without a contract.

A report in the Philadelphia Inquirer said union officials were demanding a $0.50 hourly pay raise to cover the cost of training certification for the 219 officers.

"At no time did we want to have to go on strike, but SEPTA forced our hand to do what we had to do right now," Rich Neal, of the union, told NBC10.

Read the full story on NBC10

In a statement issued on its website, SEPTA said that it did "not anticipate this labor action will affect any transit operations or service."

"SEPTA has hired a private firm to provide security at our major transit facilities," SEPTA said. "We have an agreement with the Philadelphia Police Department to immediately begin periodic checks of our stations and vehicles 24 hours a day, with an increase presence at our key stations during school dismissal between 2:00 p.m. and 6:00 p.m. and during rush hour."

NBC News and msnbc.com staff contributed to this report.