A six-month-old baby girl has been rescued from the ruins of an apartment building in Taiwan, 30 hours after it was brought down by an earthquake.

Earlier a 20-year-old man was also pulled out alive, but hopes are fading for 120 others thought to be trapped in the ruins of the Weiguan Jinlong building in Tainan City.

Most of the 26 people who died in the quake were in the building.

An investigation into its construction has been launched.

More than 170 people have now been rescued. Nearly 500 people were injured as a result of the magnitude 6.4 earthquake, and dozens remain in hospital.

Hundreds of soldiers are involved in the rescue effort, with the help of hi-tech equipment and rescue dogs, and shelters are being set up for those who have lost their homes in the city of two million people.

The BBC's Rupert Wingfield Hayes, in Tainan City, says that as the rescue goes into a second night, there is an increasing sense of despair among the relatives still waiting for news.

He adds that there is also anger, because the collapsed apartment building has exposed tin cans and blocks of white polystyrene inside some concrete pillars. Unscrupulous construction companies sometimes to use such techniques to save on concrete, and reduce costs.

Interior Minister Chen Wei-jen has said investigators will examine whether the building's construction met the required standards.

The 17 storeys of the Weiguan Jinlong (Golden Dragon) apartment complex, home to more than 250 people, crumpled down on each other as the quake took hold just before 04:00 local time on Saturday (20:00 GMT Friday).

Elsewhere in the city, at least two other victims were killed by falling debris.

A woman surnamed Chang said she was waiting to hear from her daughter, who lived on the fifth floor of the fallen block of flats.

"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," she said.

"I know they will find her, but I have also prepared for the worst," she added.

A man in his 60s, whose son escaped and whose daughter-in-law was in serious condition, was trying to help rescuers pinpoint his 11- and 12-year-old grandsons.

The quake was shallow, meaning its effects would have been amplified, the US Geological Survey said.

There were also at least five aftershocks. The quake was felt in the capital Taipei, 300km away.

Taiwan lies near the junction of two tectonic plates and often sees tremors.