* More than 130 people trapped in collapsed tower - official

* Cold weather as rescue enters second day

* All but about 30 are believed buried deep in rubble

* Official death toll from quake at 18, most from collapsed tower (Adds comment from Tainan mayor)

By Yimou Lee

TAINAN, Taiwan, Feb 7 (Reuters) - Rescuers in Taiwan pulled a young man alive from a collapsed apartment tower on Sunday more than 24 hours after a strong earthquake shook the island, and kept searching for more than 130 people believed trapped in the ruins of the building.

The 20-year-old was identified by Taiwan media as Huang Kuang-wei. He was taken to hospital.

Firefighters, police, soldiers and volunteers combed through the ruins, some using their hands, watched anxiously by dozens of the victims' family members who wore thick jackets, woollen hats and scarves on a chilly morning.

"She's not answering my phone calls ... I am trying to hold my emotions and stay strong. I'll do that until I find her," said a woman surnamed Chang, 42, waiting to hear from her 24-year-old daughter who lived on the fifth floor of the complex. "Nothing matters but to get her out. The lady living across the hallway was rescued yesterday. I know they will find her, but I have also planned for the worst. It's been more than 20 hours now." At least 18 people are known to have died in the quake, which struck at about 4 a.m. on Saturday, at the beginning of a Lunar New Year holiday, including 16 found in the collapsed Wei-guan Golden Dragon Building in the southern city of Tainan.

A total of 132 people are still beneath the rubble of the commercial-residential block, said a city government official surnamed Chen, with all but about 30 of them trapped deep in the wreckage.

The building's lower floors pancaked on top of each other in the 6.4 magnitude quake and then the whole structure toppled, raising immediate questions about the quality of materials and workmanship used in its construction in the 1990s.

QUESTIONS

Tainan Mayor William Lai told reporters that efforts were focusing on 29 people who are closest to the rescuers, with lighter equipment like drills being used.

"The other 103 are believed to be at the lower floors of the building, and we can't find an accessible route to those areas at the moment."

The extent of damage to the Golden Dragon Building has raised questions.

Liu Shih-chung, Tainan city government deputy secretary general, said television footage of its ruins suggested the possibility of structural problems related to poor-quality reinforced steel and cement.

However, city officials have said it is too early to say for certain if poor construction was a factor in the collapse.

The dead taken from the collapsed apartment block on Saturday included a 10-day-old girl who was found in her dead father's arms, media reported.

Authorities said the building had 96 apartments and 256 registered residents, though more people were inside when it collapsed.

Rescuers wearing red and yellow overalls pulled more than 240 survivors from the ruins and inserted huge supports under slabs of leaning concrete as they searched for additional survivors.

Buildings in nine other locations in the city of 2 million people had collapsed and five were left tilting at alarming angles, a government emergency centre said on Saturday.