A powerful 7.2-magnitude earthquake shook Alaska\'s Aleutian Islands late Thursday, triggering a tsunami warning that sent people heading for high ground before the alert was canceled. Hundreds of people fled the coast on foot, drove or rode in the back of pickup trucks after the earthquake struck 80 miles (130 kilometers) northeast of the seafood port of Dutch Harbor, home to some 4,400 people. The temblor struck at 7:09 pm local time (0309 GMT Friday), triggering a tsunami warning from the West Coast/Alaska Tsunami Warning Center (WCATWC). Sirens rang out, officials ordered people to move to at least 50 feet (15 meters) above sea level, and fishing boats could be seen steaming out of the harbor as a precaution in case waves struck the coast line. \"Those feeling the Earth shake, seeing unusual wave action or the water level rising or receding may have only a few minutes before the tsunami arrival and should move immediately,\" warned the WCATWC. \"Homes and small buildings are not designed to withstand tsunami impacts. Do not stay in these structures,\" officials warned. But about an hour later it was all over. \"We\'ve confirmed that no wave has been generated,\" acting public safety director Matt Betzen said at 8:21 pm (0421 GMT). \"We\'re giving the all-clear.\" The US Geological Survey originally reported the quake as a huge 7.4-magnitude, but downgraded it in subsequent hours to 7.3 and eventually 7.2. There were no immediate reports of damage or injuries along the remote island chain. Fire engines and police cars drove up and down the hillsides telling residents it was safe to return to their homes. USGS said the earthquake was at a depth of 39 miles (62 kilometers), and struck more than 1,000 miles (1,600 kilometers) west of the major Alaskan city of Anchorage. A pair of moderate aftershocks shook the Aleutian Islands early Friday.