MANADO, Indonesia (AP) – A powerful earthquake rocked eastern Indonesia on Thursday, sending residents fleeing from swaying homes and hospitals, authorities and witnesses said. There were no immediate reports of damage.

The quake, which had a magnitude of 6.9, triggered a tsunami warning but the alert was quickly lifted after it became clear no destructive waves had been generated, the country’s geophysics agency said.

In the city of Manado, people fled from markets, hospitals and schools, witnesses said. One woman ran from the second floor of a hospital carrying her son, who had an IV drip in his arm.

“What’s going on? What’s going on?” she screamed before being calmed by other people.

The earthquake struck under the Maluku Sea at a depth of 20 miles, the U.S. Geological Survey said on its Web site. The quake’s epicenter was more than 130 miles north of Ternate island.

“We felt a strong tremor for almost a minute, people ran in panic from buildings,” said George Rajaloa, a resident in Ternate. “Children are crying and their mothers are screaming, but there is no damage in my area.”

The U.S. Geological Survey initially put the quake at 7.0 magnitude, but later lowered it to 6.9.

Indonesia, the world’s largest archipelago, is prone to seismic upheaval due to its location on the so-called Pacific “Ring of Fire,” an arc of volcanos and fault lines encircling the Pacific Basin.

In December 2004, a massive earthquake struck off Sumatra island and triggered a tsunami that killed more than 230,000 people in a dozen countries, including 160,000 people in Indonesia’s westernmost province of Aceh.

Just over a year ago, another quake-generated tsunami killed around 600 people on Java island