More than 1,000 people have been rescued in flooded parts of Houston, as Tropical Storm Harvey continues to batter Texas with heavy rains.
There is a “flash flood emergency” across the Houston Metro area, with travel near impossible, the National Weather Service (NWS) says.
The NWS earlier noted reports of five deaths, but only one fatality in Houston has been confirmed.
Houston’s mayor says more than 2,000 calls asking for help have been made.
Sylvester Turner urged residents not to call emergency services unless their situation was life-threatening and they needed to be rescued.
He said a convention centre would be used as a shelter.
Two deaths have so far been confirmed from the storm since it made landfall:
- In Aransas County, where Rockport is the chief town, a person died in a house fire on Friday night
- A woman died in Houston as she drove through flooded streets on Saturday
The NWS in Houston and Galveston said that it had recorded 24.1in (61.2cm) of measured rain in the past 24 hours.
Flooding in the Houston area is expected to worsen and “could become historic”, with “potentially significant flooding also expected in other saturated areas of south-east [Texas]”, the forecaster says.
It is advising people to move to higher ground amid “an extremely dangerous and life-threatening situation”.
Residents were warned not to try to travel unless “fleeing an area subject to flooding or under an evacuation order”.
Like Houston, Galveston was also hit by “epic catastrophic flooding” overnight, the NWS added.
In Rockport: Too poor to flee the hurricane
Rescue efforts are being hampered by strong winds and thousands are without power. The US Coast Guard in Houston has requested more helicopters as more people ask for help.
Governor Abbott has mobilised 1,800 military personnel to help with rescue and repair operations.
The BBC’s James Cook, who is in Houston, says it feels like a city in crisis. Motorways are empty and abandoned cars are everywhere, he says.
Mr Abbott said another 40in of rain could be due before the storm subsides midweek.
Houston is the country’s fourth biggest city, with 6.6m people living in the metropolitan area.
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The weather service has issued flash flood emergency warnings for many counties in south-eastern Texas.
“Many creeks, rivers and bayous have flooded and have surpassed previous flood record levels,” it said.
Meanwhile, Exxon Mobil has said it is shutting down the second-largest refinery in the country, at Baytown. The Texas Gulf Coast is a key centre of the US oil and gas industry.
Harvey began as a major category four hurricane – the first to make landfall in the US in 13 years when it arrived late Friday – but was downgraded to a tropical storm later on Saturday.
It is forecast to meander across south-east Texas until Wednesday.
President Donald Trump said on Twitter that he would travel to Texas “as soon as that trip can be made without causing disruption”.
In another tweet, he said: “Good news is that we have great talent on the ground.”