JAKARTA, Indonesia — A strong earthquake hit off Indonesia's main island of Java Monday, prompting authorities to briefly issue a tsunami warning and sending thousands of residents fleeing their homes in panic.

There were no immediate reports of injuries or damage from the 6.7-magnitude quake, which struck shortly after 3 a.m. Monday (2000 GMT, 4 p.m. EDT).

The U.S. Geological Survey said the temblor was centered 318 kilometers (nearly 200 miles) off southern Java, just 24 kilometers (15 miles) beneath the ocean floor.

Thousands of people in the town of Cilacap poured into the streets and ran to high ground, many gathering in mosques, witnesses told El Shinta radio.

Ninety minutes later, when the threat of a tsunami had passed, they were told to go home.

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

A magnitude 9.1 quake and subsequent tsunami on Dec. 26, 2004, killed more than 230,000 people in a dozen nations, nearly three-quarters of them in western Indonesia. (AP)