An earthquake with a magnitude of 7.7 jolted off the coast of Flores Island in Indonesia early Saturday, the country's Meteorology, Climatology and Geophysics Agency (BMKG) said.

The epicenter was located 36 km northeast of Mbay, East Nusa Tenggara province, with a depth of 15 km, according to the BMKG, which has issued a tsunami warning following the tremor.

Strong tremors were felt in several areas, prompting many panicked residents to rush into the streets for safe shelter, local media reported.

Indonesia sits on the Pacific "Ring of Fire" and is home to more than 120 active volcanoes, making it one of the world's most volcanically active countries.