MANADO, Indonesia - A powerful earthquake in northeastern Indonesia on Tuesday caused panicked residents to flee shaking buildings on islands in the Maluku Sea and briefly triggered a tsunami warning, officials said.

The 6.5-magnitude temblor struck 210 kilometers (130 miles) from Ternate, the capital of Maluku island, and 375 kilometers (233 miles) from Manado, the northernmost city on Sulawesi island, the U.S. Geological Survey said.

"We called local authorities in Ternate and coastal areas to warn them of a potential tsunami," said Fauzi, an Indonesian seismologist who goes by only one name, adding that it turned out to be a false alarm.

One hour after the quake struck, there were no signs of seismically triggered waves.

It was not immediately clear if the temblor, which was centered at a depth of around 30 kilometers (20 miles), caused any injuries, and damage appeared to be largely limited to cracks in buildings.

Frightened residents fled their homes and at least one hotel in Ternate was evacuated.

"It was very strong, my house was shaking for 40 seconds," said George Rajaloa. "People started running into the streets, some heading to high ground."

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 Indonesia's Sumatra island and triggered a tsunami that killed more than 230,000 people _ 131,000 of them in Indonesia's Aceh province alone. A tsunami off Java island last year killed nearly 5,000.

Tuesday's tremor came less than a month after a magnitude-7.3 earthquake hit in roughly the same spot, killing at least three people.