The Obama administration is "horrified" by reports that more than 100 people were executed in a Syrian town, White House spokesman Josh Earnest told reporters Sunday, according to a White House pool report.

"We're horrified by the reports that more than 100 people were executed on May 2 …reportedly by regime forces," Earnest said. "Those responsible for serious violations of international humanitarian law, and serious violations and abuses of human rights law, must be held accountable. As Bashar al-Assad continues to cling to power, we will not lose sight of the men, women and children who are being killed by his regime."

The State Department has cited reports that Assad regime and allied forces destroyed Bayda with mortar fire, and then stormed the town, executing entire families.

Earnest wouldn't comment on the overnight airstrike Israeli warplanes carried out near Damascus. The strike was the second attack by Israelis in three days. Officials say it targeted a shipment of advanced, Iranian-made missiles believed to be bound for Lebanon's Hezbollah militants.

Earnest briefed reporters on Air Force One en route to Columbus, Ohio, where the president will give the commencement address at Ohio State University Sunday afternoon.