An undersea earthquake with magnitude of 7.1 rocked northern tip of Sumatra island earlier Wednesday, it was potential for tsunami that the people flee from coastal areas, but no damages or casualty was reported, officials said.

The quake was initially registered at 7.6 in magnitude by the Meteorology and Geophysics Agency, but the agency revised the magnitude to 7.1, an official said. The USGS reported on its website earlier that the quake was at 7.3 magnitude with the depth at 33 km under sea bed.

A tsunami warning had been issued but then the agency lifted it as the danger did not occur."We lifted the tsunami warning as it did not happen," the official told Xinhua by phone.

The quake struck at 01:36 a.m. Jakarta time Wednesday (18:36 GMT Tuesday) with epicenter at 350 km southwest Meulaboh town of Aceh province and with the depth at 10 km under sea bed, and several after shocks with magnitude of 5.4 and 5.0 followed the quake about half an hour later, the official said.

The main shock had the people living in the coastal area in Meulaboh and Ulele fled escaped the areas by up to one kilometer for fear of tsunami, along with the instruction from authorities to stay away from the coast, Ibnu Sa'ad, head of emergency unit of provincial disaster management and mitigation agency said.

He told Xinhua over the phone from Aceh province,"We have asked people in coastal areas at Meulaboh town and Ulele in Banda Aceh to leave the coastal areas by up to one kilometer from it for their safety if tsunami occurs."

Ibnu also said,"The people have rushed out their homes since the quake hit, but they did not panic," However, local Metro TV reported the quake triggered panic in Meulaboh town.

Nevertheless, Ibnu said, "So far the situation is safe". According to him, the authority have not received any report of building collapsed or damaged, or people hurts, after their officials spread to the scene.

Indonesia is vulnerable on earthquake as it sits on a vulnerable quake-hit zone so called "the Pacific Ring of Fire," where two continental plates meet that frequently caused seismic and volcanic movement in the country homed by 129 active volcanoes. Over 170,000 people were killed in Aceh when a tsunami hit Indian Ocean in Dec. 2004. The total fatality at the countries along the ocean was at about 230,000 people.