AUGUSTA — A server security breach in September has exposed account information for more than 1,300 unemployment beneficiaries, the Maine Department of Labor announced Friday.

Although the servers used by JP Morgan Chase — which contracts to run the state debit card system used by unemployment claimants — were breached three months ago, the banking giant didn’t inform Maine officials until Wednesday, a Department of Labor release states. The bank will send emails to affected Mainers on Dec. 9.

“We will hold JP Morgan Chase responsible to ensure the security of our citizens’ rights and personal privacy,” said Gov. Paul LePage in a prepared statement. “We are greatly concerned about this lapse and want Mainers to know that we take seriously the need to keep data safe.”

The bank notified DOL on Wednesday that the Web servers used by its site, www.ucard.chase.com had been breached in mid-September. JP Morgan Chase says it has fixed the problem and reported it to law enforcement.

The information that may have been exposed includes claimants’ debit card numbers, birthdays, user IDs, passwords and email addresses. PIN numbers were not exposed. No state government information systems or other unemployment system data were exposed by the breach, nor were other debit card programs operated by the state.

Several other states’ unemployment and other debit card programs managed by JP Morgan Chase were affected.

Maine Department of Labor officials have asked the bank to report what steps will be taken to inform claimants, when that would occur, why the breach happened and how security will be improved in the future.

“The Department of Labor is looking into the situation surrounding the breach and why we were not informed sooner of this event,” said Labor Commissioner Jeanne Paquette.

JP Morgan Chase says it has no reason to believe any information was used improperly, and that it will continue to monitor the exposed accounts. It is also asking cardholders to monitor their own accounts, and to call customer service if they see any purchases they do not recognize.

Unemployment benefit payments are made in one of two formats, either by direct deposit to a checking or savings account or to a prepaid debit card that can be used at ATMs, financial institutions and anywhere that the Visa logo is displayed but transaction fees apply. The debit cards may be active for up to three years, even if the person is no longer unemployed.

Paquette said DOL could not access information on cardholders, and urged debit card system users to call JP Morgan Chase at 1-866-315-1011 with any questions.