The latest quake was felt strongly on the island and followed a 6.9 quake on Sunday that killed at least 131 people and damaged thousands of houses.
A witness told Reuters the latest quake sent people into the streets in panic and caused buildings to collapse.
Journalist Robert Ovadia tweeted: “A 6.2 magnitude aftershock just rocked #Lombok.
“People screaming, panicking and running into the streets.”
Meanwhile Sutopo Purwo Nugroho, a spokesman for Indonesia’s disaster mitigation agency (BNPB), posted: ”Evacuees and people ran out of houses when they felt the strong shake of the 6.2 magnitude quake. People are still traumatised.
“Some buildings were damaged further because of this quake.”
Officials said the quake’s epicentre was on land and so there was no risk of a tsunami.
The United States Geological Survey (USGS) recorded the latest quake at 5.9, with a depth of 10 km (6 miles).
BNPB’s official death toll from Sunday’s quake stood at 131 on Wednesday, although some Indonesian officials put the number at 347. Sutopo did not give an updated toll, telling Reuters only that there had been “a big increase”.
A humanitarian crisis is also looming in Lombok, where thousands have been left homeless and in desperate need of clean water, food, medicine and shelter.
Officials said about three-quarters of Lombok’s rural north had been without electricity since Sunday, although power had since been restored in most areas. Aid workers have found some hamlets hard to reach because bridges and roads were torn up by the disaster.
Thousands of tourists have left Lombok since Sunday, fearing further earthquakes, some on extra flights provided by airlines and others on ferries to the neighbouring island of Bali.
A total of six earthquakes have hit Indonesia in the last 48 hours, following on from last Sunday’s massive tremor.
(More to follow)