GALVESTON, Texas (AFP) - Millions of people remained without power and water Monday as deadly Hurricane Ike barreled up from the Gulf Coast into the Midwest, reportedly leaving more than 15 dead across nine states. Massive search and recovery operations were ongoing in storm-battered Texas, with nearly 4,000 people rescued across the state. Texas Governor Rick Perry said Monday it could be "weeks" before residents can return to Galveston, the devastated island city in the eye of the storm's surge, and they were urged to stay away until the situation improves. The death toll would also likely rise as the clean-up continued, officials said. An estimated 20,000 people on the Texas coast ignored evacuation orders and tried to ride out Ike when it made landfall early Saturday, bringing with it a wall of water and ferocious 110-mph winds. The Category Two storm carved a path of destruction from the Mississippi Valley to the Great Lakes, with hurricane-force winds hitting Kentucky and flooding reported as far north as Chicago, Illinois. In southern Texas and Louisiana alone 2.6 million homes and businesses were left without power, according to the US Department of Energy. Rubble-strewn Houston, the fourth most populous US city, has imposed a week-long night curfew because of flooding and the danger of downed power lines. Simon Chabel of the Federal Emergency Management Agency (FEMA) told AFP that as of late Sunday 3,743 people had been rescued throughout Texas after Ike blew the roofs off houses, felled trees, and flooded roads. Officials advised residents sheltering outside the region to stay away until conditions improved. "Galveston has been hit hard. We have no power. We have no gas. We have no communications. We're not sure when any of that will be up and running," Mayor Lyda Ann Thomas said. "Do not come back to Galveston," she said in a plea to her city's residents. "You cannot live here at this time." President George W. Bush said he would travel to Texas on Tuesday to witness the devastation at first hand, and promised food and water deliveries after meeting FEMA director David Paulison in Washington. Three US-based risk assessment firms tagged the onshore damage at anywhere between eight and 18 billion dollars (5.6-12.7 billion euros). Houston Mayor Bill White on Sunday questioned why FEMA had not yet begun delivering vital food, water and ice to residents of his stricken city. "We expect FEMA to deliver those supplies and we will hold them accountable in this community," White said. Officials said Sunday at least 10 offshore oil platforms were damaged in the storm, while Houston-area oil refineries that produce 20 percent of the nation's gasoline remained shuttered and offline, causing fears to mount of an impending gasoline crunch. Authorities warned it could be weeks before electricity was restored to some customers, prompting authorities in Houston to announce a dusk-to-dawn curfew to prevent looting and help prevent accidents on roads strewn with fallen trees and live power lines. More than 2.2 million residents across the area fled inland to avoid Ike's wrath, but more than 100,000 residents of low-lying areas " including 20,000 in Galveston " decided to ride out the storm despite warnings of "certain death" from the national weather service. Crude oil prices fell nearly two dollars on Sunday in New York, dipping below 100 dollars to 99.30 dollars, as traders were reassured that refineries and rigs had been spared the worst. Gasoline prices at pump stations, however, spiked in the southeastern US and officials warned they would punish firms engaged in price-gouging. Heavy rain overnight Sunday in Houston aggravated flooding and authorities advised evacuees to hold off on returning home while roads were still blocked and traffic lights out. "We're asking people just to be patient," FEMA director Paulison told CNN on Sunday. "Don't be in a hurry. If you're in a safe place, whether a shelter or hotel or motel, or staying with friends and family, just stay right there."