Power outages leave millions shivering in deadly US cold snap

Millions of Americans were struggling without electricity Wednesday as bitter cold from a deadly winter storm system held its grip across huge swathes of the United States, even pushing as far south as Mexico.

The Arctic weather system -- which has seen temperatures plummet to record-setting lows in places ill-prepared for such conditions -- has overwhelmed local utility companies, infuriating residents left to huddle under coats and blankets and fend for themselves.

In Texas, power companies have implemented rolling blackouts to avoid grids being overloaded as residents cranked up electric heaters. Some people have been without power for days.

"Spending my second night without power during the coldest weather in Southeast Texas in more than 30 years," Wes Wolfe, a newswriter in Lake Jackson, Texas said on Twitter.

"Eating half a falafel wrap by laptop light for dinner, before getting under my blankets, which are augmented by a heavy overcoat."

According to the Poweroutage.us tracker, nearly three million residential, commercial and industrial customers in Texas remained without power Wednesday morning.

This week's surge in electricity demand came just as icy conditions knocked gas-fired power stations offline and saw wind turbines freeze to a standstill.

The American Red Cross said it had opened over 35 warming centers across Texas.

More than 20 storm-related deaths have been registered since the cold weather arrived last week, including in traffic accidents in Texas, Kentucky and Missouri.

At Primarily Primates, a wildlife sanctuary near San Antonio, Texas, several animals reportedly died when staff were unable to warm them after the facility lost power Monday.

Brooke Chavez, the center's executive director, told the San Antonio Express-News that a chimpanzee, several monkeys, lemurs and tropical birds had perished.

In the small western Texas community of Colorado City, the mayor resigned after telling residents impacted by a power outage to "come up with a game plan" and "get off your ass and take care of your own family!"

"I'm sick and tired of people looking for a damn handout!" Tim Boyd wrote on a now-deleted Facebook post.

According to the National Weather Service (NWS), more than 71 per cent of the continental United States was covered in snow Wednesday.

The storm system was expected to move towards the northeastern US and begin to loosen it grip over the central and southern parts of the country by Thursday, the NWS said, while warning of ongoing treacherous conditions.

"Crippling" ice accumulations were possible in parts of Texas, Louisiana, Arkansas and Mississippi.

"In the areas that contend with these devastating ice accumulations, residents can expect dangerous travel conditions, numerous power outages, and extensive tree damage," the NWS said.

While several of the weather-related deaths so far have resulted from traffic accidents, Houston police said a woman and a girl died from carbon monoxide poisoning after sitting in a garaged car with the engine running to keep warm.

A man in Louisiana died when he hit his head after slipping on ice, and a 10-year-old Tennessee boy perished after he and his six-year-old sister fell through the ice into a pond Sunday.

The winter storm spawned at least four tornadoes, according to Atlanta-based weather.com, including one in coastal North Carolina late Monday that killed at least three people and injured 10 more.

Across the southern border, Mexican officials said six people died after temperatures plunged and frozen pipelines bringing natural gas from Tim Boyd the United States caused rolling power outages.

Four died in Monterrey, three of them homeless people who succumbed to exposure and one person who died at home from carbon monoxide poisoning from a heater.

Two agricultural workers also died in neighbouring Tamaulipas from hypothermia.