The blast took place when officers were participating in noon prayers in the mosque. Ten of the 13 killed were emergency force members; the rest were others who worked at the site.
The US, Pakistan, Germany and other countries have condemned Thursday's terrorist bombing at the mosque.
This is the third Saudi Arabia mosque attack claimed by ISIS since May.
At least 30 people were killed and 150 injured on May 22 when suicide bomber blew himself up at the Imam Ali mosque in the village in Saudi Arabia
A week later, a man disguised as a woman blew himself up -- killing three people -- outside a mosque in a predominantly Shiite neighborhood of Damman, the capital of Saudi Arabia's oil-rich Eastern Province.
Saudi Arabia has launched numerous airstrikes in Yemen this year in support of that country's deposed president.