JAKARTA - A magnitude-6.1 underland quake struck in Lampung province of Indonesia's Sumatra Island on Monday (May 2) morning, Xinhua reported.

"The centre of the quake was underearth and its shakes were strongly felt by the communities," Xinhua quoted meteorology and geophysics agency official Dede Yunus as saying.

The epicentre was 23km south-west of Tanggamus town, and its depth was 115km under the earth, according to the official.

The tremblor occurred at 11.21am Jakarta time.

Mr Yunus also said the intensity of the quake was felt in the towns of Krui and Liwa, at 4 on the Modified Mercalli Intensity scale.