(CNN) Four days after a massive earthquake killed hundreds on the Indonesian island of Lombok, a 5.9 magnitude tremor hit the island, sending frightened residents out into the streets.

Thursday's seismic event follows a 6.9 magnitude quake Sunday that flattened homes and stranded thousands on Lombok's northern coast and the nearby Gili Islands.

North Lombok, more residential and less developed than the island's resort-filled south, was devastated by Sunday's quake. Some villages in the region were completely destroyed, witnesses told CNN.

Aid has been slow to trickle in, due to damage to roads leading to the affected areas and the relatively remote location of the island. Rescue workers have been searching debris for days in the hopes of finding people alive amid the rubble.

Hundreds who survived Sunday's quake are huddled in evacuation centers, where they sleep on plastic mats. Food is scarce, and some of the children are eating crackers dipped in chili sauce.