Houston - Hurricane Ike continued battering northern regions of Texas with 145-kilometre-an-hour winds Saturday, even as residents of the coast and Houston started a cautious survey of the damage after the storm had moved through.

There were three reported deaths, including a young boy killed by a falling tree as his family tried to clean up damage after the storm had passed, CNN reported.

The fate of an estimated 90,000 people who refused to evacuate in Galveston Island, on the coast, and the surrounding counties was not yet known.

Ike hit the coast in the early hours of Saturday with winds over 170 kilometres an hour. In Houston and Galveston, water stood as high as 2 metres in the street.

The Galveston city manager, Steve LeBlanc, asked journalists on Saturday to use discretion when filming, out of concern they may find massive corpses.

"We do not know what we are going to find," said Lyda Ann Thomas, mayor of Galveston. "We hope to find those who did not evacuate are still alive and well."

Sixty-four kilometers inland, Houston awoke to a city of broken glass and felled trees.

The wind had snapped off trees at ground level and picked up a huge high-rise-building air conditioning unit from the roof and dumped it in the street, a local businessman told CNN.

Centerpoint Energy, the main power company in the region, said that about 1.8 million - or 90 per cent - of its customers were without power, and warned it would be at least two weeks until power was fully restored.

Houston Mayor Bill White asked residents to boil their water due to the low pressure which may have allowed some outside contaminants to infect the system. The pressure dropped because some of the pumps lacked power.

"The rule of thumb is: use bottled water," he said in broadcast remarks.

He also urged healthy adults to share their bottled water with seniors and infants who are most susceptible to the ill effects of dirty water.

"Many people may not be able to boil their water because of the situation with electricity," he said.

Officials were urging people to stay inside until the worst of the winds had passed. Downed power lines were one of the chief dangers.

"Please keep out of the streets, and this is no time to play in the ditches," the Houston mayor said.

Fire and rescue services were unable to answer hundreds of calls in Galveston as the storm moved through, and in Houston, there was a backlog of more than 5,000 calls.

Only about 250,000 people in Houston were under mandatory evacuation from the country's fourth largest city of 4 million.

In Galveston, officials had issued the sternest of warnings for a full evacuation and warned they would have to ignore any calls for rescue until daybreak.

There were several hundred calls, broadcast reports said, and several fires that burned unattended because of the storm.

The Federal Emergency Management Agency (FEMA) on Friday said it expected up to 100,000 homes in the entire Houston region to be flooded or destroyed.

Thousands of army and air force national guard troops, along with outlying fire and rescue people, were waiting with thousands of vehicles north of the hard-hit region to move in with emergency aid and emergency evacuations.

In Galveston, earliest video images via CNN showed the storm had chopped up asphalt and tossed the pieces around like so many boulders.

Huge chunks were falling off buildings that were still standing.

The gravest problem from Ike was the tidal surge.

Owing to Ike's large diameter, meteorologists compared its effects to that of a category 5 hurricane, even though it was only a category 2 on the Saffir-Simpson's five-level scale at landfall.

Despite several warnings and a mandatory evacuation order issued Thursday, many residents in Galveston decided to stay and weather the storm at home.

Many considered the official announcements exaggerated, thought their homes were strong enough or rejected risking a chaotic evacuation like that of hurricane Rita in 
2005.

A few also mentioned a wish to live through the storm at its worst.

Galveston is known for its nearly 6-metre-high seawall built to protect historic old homes which survived the lethal storm of 1900.

In 1900, up to 8,000 people died after a huge hurricane hit Galveston, causing the deadliest natural disaster in US history.

In 2005, Hurricane Katrina killed about 1,800 people in New Orleans and the surrounding Gulf coast.

Ike has already killed at least 72 people in Haiti and five people in Cuba as it churned across the warm Gulf of Mexico waters since last weekend. (dpa)