A computer virus may be to blame for some Newark city employees not receiving their paychecks last week.

A spokesperson for Mayor Ras Baraka’s office says that the city’s computer system was compromised by a virus on Friday, which affected the ability to write checks. It also disrupted many other services that Newark officers online.

The city says that it is working to get those employees who weren’t paid debit cards as quickly as possible.

But a Sanitation Department employee working through the city’s prisoner reentry program says that he was told as early as last Tuesday that employees might not get paid. The worker, who wished to remain anonymous, says that he and his coworkers are frustrated with how they are being treated.

“Unfortunately for them, the computer system was hacked when the reentry guys were supposed to be paid,” he says. “We called the mayor’s office. We called aides. We left our numbers and nobody called us.”

Newark Chief Information Officers Seth Wainer said in a statement, “City government is operating in ‘safe mode’ as we inspect each service to look for security gaps. This means some of our digital services are unavailable.”

Wainer went on to say, “We understand this causes an extreme disruption to residents who have come to depend on regular services – and we apologize.”

The city says it wants to assure residents that police services were not affected by the computer outage. The city is working with state and federal law enforcement agencies to determine how the attack happened.

Wainer would not comment on how many employees were not paid due to the issues.