A Texas mother is behind bars after her two children died after reportedly being left in a hot car for hours, according to authorities.

Sept. 22 (UPI) -- A Texas mother is behind bars after her two children died after reportedly being left in a hot car for hours, according to authorities.

Tiona Lasaisha Islar told sheriffs deputies in Bexar County near San Antonio she allegedly found her two children, 3-year-old Miyani Islar and her autistic 6-year-old brother Sevani Stevenson, in her vehicle on Saturday after 3 p.m. local time.

But according to Sheriff Javier Salazar, something is "not adding up with this case."

Islar, 28, claimed she last saw her two children that morning around 10 a.m. before she dozed off and reportedly took the two kids inside the home before dialing 911.

Miyani and Sevani were officially identified by the Bexar County medical examiner's office.

Officials said the examiners report could be released as early as Monday.

On Saturday, Salazar said CPR had been performed, however, the children died on scene.

"The initial report was for children who were left in the car but I can tell you that unfortunately, without going into too much detail, there just are some inconsistencies with the stories at present," said Salazar.

"I'm not confident enough to tell you all that's definitely what happened," he added during a media update in both English and Spanish.

Islar has been given two charges with injury to a child causing serious bodily injury and death.

A local judge set her bail at $300,000.