TAIPEI, Taiwan (CNN) A major aftershock from Tuesday's killer earthquake rattled Taiwan on Sunday, even as rescuers continued to retrieve survivors of Tuesday's quake from ruined buildings around the island.

The 6.5-magnitude aftershock rattled central Taiwan, leaving two motorists dead after a landslide injuring at least 15. Several buildings already damaged by Tuesday's earthquake, which killed more than 2,000 people island-wide, collapsed after the jolt.

But about three hours after the new tremor, rescuers pulled two brothers alive from the wreckage of a Taipei hotel demolished in the first earthquake. Sun Chi-kwang, 20, and Sun Chi-feng, 25, survived their130-hour ordeal by drinking water sprayed
over the rubble and their own urine, and by eating apples, they told rescuers.

Sun Chi-kwang, the first to emerge, swigged bottled water and shielded his eyes from searing daylight he had not seen since Monday.

"He said he ate rotten apples in the fridge and drank what he thought was rain water, though that was the water that we poured  in," Taipei Mayor Ma Ying-jeou said.

Both brothers were recovering at a military hospital after their rescue. Ma said several others may be clinging to life in the wreckage of the downtown Sungshan Hotel, where rescuers had all but given up hope of finding new survivors on Saturday.