JAKARTA, Indonesia (CNN) -- Another strong earthquake rocked Indonesia early Thursday as the Southeast Asian nation was reeling from an earlier jolt that killed more than 200 people.



A resident stands next to building that collapsed onto a car in Padang, Indonesia, on Wednesday.



The 6.8 magnitude quake Thursday hit southern Sumatra at 8:52 a.m. local time (0152 GMT), the Pacific Tsunami Warning Center said. Wednesday's earlier quake was 7.6 magnitude.



At least 236 people are dead and more than 500 injured, the Indonesian Social Ministry's Crisis Center said Thursday. It said it had little information on the missing and feared the death toll would climb into the thousands.



The second quake was on a smaller scale than the first, said meteorology official Fauzi, who uses only one name. There were no damage reports yet.



Indonesian Health Minister Siti Fadilah Supari expected "the casualties and the damage of this earthquake to be bigger than the 2006 Yogyakarta earthquake, given the intensity and the spread of the damage."



The magnitude-6.3 Yogyakarta quake in central Java in May 2006 killed more than 5,000 people, triggered fears of an eruption of a nearby volcano and caused significant damage to a 9th century Prambanan temple.



Thousands may be trapped by collapsed buildings and houses, Rustam Pakaya, the head of the Health Ministry's crisis center, told CNN on Wednesday.



State-run Antara news agency cited Pakaya as saying he had received reports that part of a hospital had collapsed and that people were buried under the debris.



The temblor struck around 5 p.m., about 33 miles (53 kilometers) from Padang, the capital city of West Sumatra and home to more than 800,000 people.



The quake caused widespread power and phone outages, making it difficult to assess damage.



Aid agencies kicked into gear to help those in need.



"We had aid ready because this area of Indonesia is susceptible to this type of tragedy," said Jane Cocking, humanitarian director for Oxfam. "Communications with the quake-zone are difficult and we are hoping for the best but having to plan for the worst."



"The situation is quite devastating," said Amelia Merrick, the operations director for World Vision Indonesia.



"Bridges have gone down, phone lines are in total disrepair. It's difficult for us to assess the situation," she said. The organization had said it would send assessment teams to the area Thursday morning.



"We know there's no electricity tonight... many of the families will be spending the night outdoors, in pitch black. I'm very afraid of what might happen next," she said, referring to the possibility of aftershocks.



Hundreds of houses have been damaged, Wayne Ulrich, the Red Cross disaster management coordinator in Indonesia, told CNN. "We do not know the [exact] numbers."



"We have concerns that a hospital has been partially damaged, a market has caught on fire, the airport was closed down for inspection because of the fear if they landed any planes," it might cause problems, Ulrich said.  Watch Ulrich discuss the rescue efforts »



Access to the affected areas was obstructed in parts, he added.



It's "blocked by all kinds of problems: frightened people out in the streets, cars, and people trying to get out of the city."



The earthquake was felt in nearby cities, such as Medan and Bengkulu, where people panicked and ran outside in search of higher ground, fearing a tsunami.



But it was also felt as far away as Singapore and Malaysia.



"I did feel the tremor in office today somewhere between 5 - 6 p.m.," said Ratna Osman, who works in a single-story office building in Petaling Jaya, just outside Malaysia's capital Kuala Lumpur.



"I asked [a co-worker] if there's an earthquake somewhere -- either that or I was hallucinating."



"At first, I thought the chair I was sitting on had a screw loose or something," Osman said.



The region is accustomed to earthquakes, and locals
where id dthe quake happen what agencies helped What is feared after the second quake? What is the main subject of the article? how many people died
southern Sumatra Aid the death toll would climb into the thousands. earthquake more than 200
question: where id dthe quake happen, answer: southern Sumatra | question: what agencies helped, answer: Aid | question: What is feared after the second quake?, answer: the death toll would climb into the thousands. | question: What is the main subject of the article?, answer: earthquake | question: how many people died, answer: more than 200