Storms and floods have killed at least 31 people in Texas, Oklahoma and Mexico, officials reportedly said Tuesday. At least 12 people were killed in Texas and 11 were reported missing in the state's Hays County, which was ravaged by high winds and record floods, CNN reported.

Oklahoma Medical Examiner's office said at least six people died in the state due to weather-related accidents over the Memorial Day weekend, Reuters reported, adding that more rain is expected this week in the two American states, increasing the possibility of a rising death toll.

Over 200 flights from Houston and Dallas were canceled by early Tuesday, while nearly 100,000 people in Texas lost power amid storms and rising water level. Four people died in Houston, from where about 1,000 calls for help were received, officials said Tuesday, according to CNN.

"It happened so fast. Every person that died in the flooding, I know what was going through their minds. They didn't measure the threat accurately. They were like me," Dutch Small, a Houston resident, said, according to Reuters.

In Mexico, at least 13 people were killed after a tornado struck Ciudad Acuna city. 

Ciudad Acuna's Mayor Evaristo Perez Rivera, said, according to NBC News, that 300 people received treatments at local hospitals after the tornado struck the city, while nearly 200 houses were destroyed to the ground. Among the people who died in Mexico, four were infants.

However, there are discrepancies in the number of deaths in different reports. According to an NBC News report, seven people have been reported dead in Oklahoma, including a firefighter from Claremore, who died during a water rescue. Another woman reportedly died in the state’s Bryan County after a tornado struck the region. NBC also reported that 14 people were missing in Texas, while nearly 700 homes in Harris County, which includes Houston, sustained damage of some sort, according to a spokeswoman for the county.

"We tried to do as much as we could, saved the family portraits and stuff like that, but everything else is destroyed," Yesenia Lopez, a resident of Texas' Harris County, said, according to CBC News, adding: "Everything is scary. That's the first time I lived through something like this, so it gives you a lot to think about."