Nearly 700 trekkers headed down Mount Rinjani on Indonesia's tourist island of Lombok on Monday, a day after a powerful magnitude 6.4 earthquake terrified the climbers as boulders tumbled down the slopes of the volcano.

Officials said the death toll from Sunday's earthquake, which was centered on the northern part of Lombok, but was also felt on the resort island of Bali to the west, stood at 16. More than 335 people were injured, many by collapsing buildings.

"I thought I was going to die," said John Robyn Buenavista, a 23-year-old American, who was at the summit when the quake hit. "I was clinging to the ground. It felt like it lasted forever. I saw people fall off, but it's a blur."