Footage from news channel Metro TV showed what appeared to be hundreds of victims being treated in a hospital parking lot and some buildings in Cianjur reduced almost entirely to rubble as worried residents huddled outside.
Other TV channels showed victims hooked up to intravenous drips and being treated on the sidewalk.
Officials were still working to determine the full extent of the damage caused by the quake, which struck at a relatively shallow depth of 10 km, according to the weather and geophysics agency (BMKG).
Muchlis, who was in Cianjur when the quake hit, said he felt “a huge tremor” and his office walls and ceiling were damaged.
“I was very shocked. I worried there would be another quake,” Muchlis told Metro TV, adding that people ran out of their houses, some fainting and vomiting in response.
Less than two hours after the quake, 25 aftershocks had been recorded, BMKG said, adding there were concerns about the potential for more landslides in the event of heavy rain.
In Jakarta, some people evacuated offices in the central business district, while others reported buildings shaking and furniture moving, Reuters witnesses said.
In 2004, a 9.1 magnitude quake off Sumatra island in northern Indonesia triggered a tsunami that struck 14 countries, killing 226,000 people along the Indian Ocean coastline, more than half of them in Indonesia.
