OTTAWA -- The Ottawa Carleton District School Board is apologizing for an overnight phone call to parents.

The board used both phone and voice messages around 12:30 a.m. to let parents know that schools are closed today due to the one-day strike by the Ontario Secondary School Teachers Federation.

Parents complained on social media about the robo-calls overnight, saying it woke them up. The OCDSB also announced the decision to close schools on its Twitter and Facebook accounts.

On Facebook, one parent said “I completely support the walkout but the phone call at 12:20 a.m. was a really poor planning choice."

Another parent said “It is very startling to get phone calls in the middle of the night. Especially on a home phone.”

One parent said “Add me to the list of pissed off parents, getting a phone call at 12:30 a.m. is very startling, and makes me think there’s an emergency.”

In a statement to CTV News, the OCDSB said "we understand the concerns that some families have raised about using both phone and voice message at 12:30 am to communicate that schools would be closed today. We apologize for the disruption. We were aware how important this message was for many families, and wanted to maintain our commitment to notify the community as quickly as possible after OSSTF made its decision known. This was an unusual circumstance and we will take the feedback into consideration for future planning."