A powerful earthquake rocked Indonesia's Central Java province early Saturday, flattening buildings and killing at least 309 people, hospitals and officials said. Scores of other people were injured.

The 6.2-magnitude quake also triggered heightened activity in the region's deadly Mount Merapi volcano, which has been spewing out clouds of hot ash, gas and lava for several weeks, a scientist said.

The quake struck at 5:54 a.m. (2354 GMT), 25 kilometers (15 miles) southwest of the city of Yogyakarta, causing damage and casualties there and in at least two other nearby towns, officials said.

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Five and half hours after the quake struck, at least 309 bodies were lying in seven hospitals in the region, and more injured and dead people were still arriving, according to morgue officials contacted by The Associated Press by telephone.

"Please tell the central government to send help, we need help here," said Kusmarwanto of Bantul Muhammadiyah Hospital, the closest hospital to the quake's epicenter.

"There so many casualties. Houses ... are flattened. Many people still need to be evacuated," he said, adding that his hospital alone had 39 dead bodies and that numbers there were rising.

The quake cracked the runway in Yogyakarta's airport, closing it to aircraft until at least Sunday while inspections take place, Transport Minister Hatta Radjasa said.

Electricity and communications were also down in parts of Yogyakarta, police said.

"It felt really powerful, and the whole building shook," said Narman, a receptionist who goes by one name at a hotel in Yogyakarta. "Everyone ran from their rooms."

In the chaos that followed the quake, rumors of an impending tsunami sent thousands of people fleeing to higher ground in cars and on motorbikes. The city is around 30 kilometers (18 miles) from the sea, and more than three hours after the quake no tsunami had occurred.

The Pacific Tsunami Warning Center in Hawaii said it has not issued any tsunami warnings from the quake. Japan's Meteorological Agency also said there was no danger of quake-generated giant waves.

The quake's epicenter was close to the Mount Merapi volcano, which has been rumbling for weeks and sending out large clouds of hot gas and ash. Activity increased as a result of the temblor, with one eruption that came soon after the quake sending debris some 3.5 kilometers (2 miles) down its western flank, said Subandrio, a vulcanologist monitoring the peak.

"The quake has disturbed the mountain," he said.

There were no reports of injuries as a result of the eruption.

Activity at Mount Merapi, one of the world's most active volcanoes, has picked up in recent weeks and almost all villagers living near the danger zone have been evacuated.

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.