Texas Flood 'Tsunami': Death Toll Keeps Rising

Thirteen people are missing in Texas after flash floods that have already claimed at least 16 lives in that state and Oklahoma.

The Hays County commissioner in central Texas said earlier they were looking for 30 people along the swollen Blanco River, but most have since been accounted for.

The floodwaters kept rising on Tuesday as storms dumped yet more rain on the already deluged Houston area.

Among the missing are members of two families who were in a holiday home that was swept away over the weekend.

The property in Wimberley, Texas, was lifted off its foundations and slammed into a bridge on the Blanco River, which is at three times its normal level.

Laura McComb, who is missing with her two children, reportedly called her sister as the home was uprooted.

"We are in a house that is now floating down the river," she said, according to KXAN-TV. "Call Mom and Dad. I love you. And pray."

Three fatalities were confirmed in Houston on Tuesday morning.

Swathes of America's fourth largest city have been inundated and more than 1,000 vehicles submerged on swamped roads.

Fans at Monday night's Houston Rockets baseball game stayed in the Toyota Center arena until the early hours because of the extreme weather.

Residents have been urged to stay off roads with many of the routes into the city flooded and blocked by stalled vehicles.

Some 100,000 householders were without electricity across Texas because of the storms.

More than 1,000 homes have been damaged or destroyed and thousands of residents displaced.

President Barack Obama said on Tuesday he had assured Texas Governor Greg Abbott that he could count on help from the federal government.

Governor Abbott, who has declared a disaster in 37 counties, said: "This is the biggest flood this area of Texas has ever seen.

"It is absolutely massive - the relentless tsunami-type power of this wave of water."

Among the dead are an 18-year-old swept away by floodwaters in Devine, Texas, as she drove home from her school prom on Saturday.

A 14-year-old boy's body was found in a storm drain on Monday morning along with his dog in DeSoto, Texas.

A firefighter was also swept into a storm drain in Claremore, Oklahoma, while attempting a rescue on Sunday.

The system is among a line of storms that have drenched areas from the Gulf of Mexico to the Great Lakes.

There was a devastating tornado in a northern Mexican border city on Monday, leaving at least 13 dead and others missing.

It swept through Ciudad Acuna, flipping over cars, tearing down homes and ripping a child from its mother's arms .