LOMBOK, INDONESIA — Rescue and evacuation operations are underway after several Indonesian islands were rocked by a deadly earthquake and strong aftershocks.

Reuters reports that Indonesia's holiday island of Lombok was hit by a magnitude 6.9 earthquake around 6:46 p.m. on Sunday. According to the USGS, the quake had a depth of 31 kilometers and was felt in neighboring Bali.

The powerful tremors triggered panic across the islands, as people fled homes and buildings and ran onto the streets. At least 91 people have been confirmed dead, most of them killed by falling rubble in northern and western Lombok. Hundreds more are reportedly injured.

The earthquake triggered an initial tsunami alert warning of waves up to half a meter, though this was later cancelled.

It's the second to occur in Lombok in a week, after a 6.4 quake that shook the island on July 29 claimed 17 victims.

More than 120 aftershocks, some ranging in magnitude from 4.3 to 5.4, were recorded following the massive quake. The death toll is also expected to rise as more news trickles in from the hardest-hit parts of the island.