A Matamoros mother remains behind bars while authorities wait on autopsy results to determine the cause of year 8-year-old daughter's death.

The Metro Noticias de Tamaulipas newspaper reported the arrested of 36-year-old Araceli Mar Sierra on its website Wednesday.

The newspaper reported that Sierra's 8-year-old daughter died at their Colonia Las Culturas home early Monday morning.

Investigators believe that Sierra drowned her daughter in the bathroom toilet because her hair and socks were soaking wet.

Family members told Metro Noticias de Tamaulipas that the second-grade girl was having trouble breathing and couldn't vomit.

They claim that the 8-year-old girl had been given glass of water when she started to panic.

Metro Noticias reported that the girl was rushed to a local hospital where she died.

The newspaper reported that close to 60 family members, friends and the girl's teachers urged authorities to release Sierra.

The 36-year-old Matamoros mother remains in custody at a state jail while family members secure an attorney and authorities wait on autopsy results.

Click here for the full story from Metro Noticias de Tamaulipas in Spanish