Officials in Texas are evacuating the most vulnerable citizens as Hurricane Ike takes aim at the Gulf Coast.

Tourist Islands Rebuild | Track Ike

The frail and elderly are being put aboard buses as authorities warn 1 million others to head inland.

Ike is expected to blow ashore early Saturday somewhere between Corpus Christi and Houston, and some forecasts said it could become a Category 4 storm, with winds of at least 131 mph.

Four counties south and east of Houston have announced mandatory or voluntary evacuations, and authorities are moving weak and chronically ill patients by bus to San Antonio.

South Texas is already getting ready for Ike. Some schools have called off classes through the end of the week, and medically fragile residents are getting on buses to head north.

Officials also opened up a shoulder lane on Interstate 37 to accommodate heavier traffic as residents decide to evacuate.

Cuba Still Reeling From Ike

Hurricane Ike roared across Cuba west of the densely populated capital's aging buildings Tuesday after tearing down the length of the island nation, ravaging homes, killing at least four people and forcing 1.2 million to evacuate.

Winds howled and heavy rains fell across Havana, where streets were empty. Towering waves broke over the graceful Malecon seaside promenade, which police had barricaded off the previous evening. Many of the historic apartment buildings along its length are in poor repair and vulnerable to collapse.

Police spread out across the city to halt all but emergency and official traffic. Roadways were strewn with tree branches and rocks, and the rubble from crumbling balconies littered sidewalks. Navigation was banned in Havana Bay, its usually placid surface stirred up by white-capped waves.

No one was killed when Gustav tore across western Cuba -- the same area Ike was pounding Tuesday -- as a monstrous Category 4 hurricane on Aug. 30, damaging 100,000 homes and causing billions of dollars in damage. That was largely because 250,000 people were evacuated.