A strong earthquake measuring 7.0 struck off the coast of Indonesia’s Sumatra island on Thursday, briefly triggering panic and a tsunami alert, the Indonesia meteorological agency said.

The quake struck in the Indian Ocean about 135 km off the town of Bengkulu at 4:02 am (0232 IST), at a depth of 10 km, the agency said.

The US Geological Survey measured the quake at 7.1. The earthquake rattled the same area hit by a massive 8.4-magnitude quake and a multitude of aftershocks last month that left 23 people dead.

Bengkulu resident Titi Radiah said that “everyone ran out of their houses.” “I was awakened by the jolt and ran out taking my baby,” she said, adding that in her neighbourhood people stayed outside for about an hour before daring to return home.

She said there did not appear to be any damage in her area. The meteorology agency warned a tsunami could strike after the pre-dawn quake but lifted its alert about an hour later.

Tsunami alerts here are issued based on the likelihood of waves striking rather than a detected change in sea levels.

A nationwide tsunami warning system is still being installed across the Indonesian archipelago and a regional system is also under construction.

Indonesia sits on the so-called Pacific Ring of Fire, where continental plates meet and where earthquakes are a regular and often deadly occurrence.