KAOHSIUNG, Taiwan (AFP) - Shocked residents in a Taiwanese neighbourhood rocked by multiple deadly gas blasts called on authorities Saturday to relocate a number of industrial pipelines running underneath the country's densely populated second city.

The explosions sparked massive fires which tore through Kaohsiung's Cianjhen district late Thursday, killing at least 26 and leaving a yawning trench running for hundreds of metres down a series of major thoroughfares.

The blasts were so powerful cars were flipped upside down whilst a moped landed on the roof of a five storey building. Nearly 300 people suffered injuries, including serious burns, during the explosions and subsequent inferno.

As rescuers continued the grim search for human remains buried under the rubble, many residents accused the southern city's authorities of acting too slowly to stop the gas leaks which locals said were first reported three hours before the explosions struck shortly before midnight.

"I think the authorities didn't handle this well, if they had turned off the pipelines right away there would not have been any explosion that followed," local resident Lin Chung-hua told AFP.

"The tragedy could have been prevented if the source of the leak was located at the first possible time and the pipelines shut down," added a 60-year-old restaurant owner who declined to give his name.

Khaosiung lies adjacent to a huge petrochemical complex housing dozens of plants and many pipelines run under the densely packed city.

Lin, whose shop lies on one of the streets torn apart by the blast, said he wanted the pipelines relocated.

"The pipelines were installed many years ago when our neighbourhood was not densely populated but now there are so many people living here. Of course they have to be removed because they are unsafe," he said.

Kaohsiung's city government has defended its handling of the crisis, saying it was "racing against time" and had carried out the correct measures once the leaks were reported.

- Firefighters still missing - ============================== The United Daily News quoted an unnamed firefighter who said the pipelines should have been shut down sooner.

"The blasts wouldn't be so devastating if the (pipelines) valves were shut earlier," he was quoted as saying.

Four firefighters who rushed to the scene after residents smelled gas were among those killed in the blasts while rescuers were searching for two others still unaccounted for.

Early Saturday rescuers and soldiers dug up a badly burned body buried under rocks and debris.

Kaohsiung mayor Chen Chu said the tragedy had "shocked residents tremendously" as she called on the central government to review the city's network of pipelines.

"I instructed relevant units to thoroughly inspect the pipelines and call for the central government to review how to properly locate them so residents do not live under invisible threats and to prevent another tragedy," she said in a statement.

It is not the first time Kaohsiung has experienced a fatal gas blast. In 1997, an explosion killed five people and injured around 20 when a team from the state-run Chinese Petroleum Corp. tried to unearth a section of gas pipeline in a road construction project.

The latest explosions were the second disaster to strike Taiwan in just over a week, after a TransAsia Airways plane crashed with the loss of 48 people last Wednesday.

Premier Jiang Yi-huan has pledged to clarify the cause soon and said flags would be flown at half-mast at government offices and schools across the island from August 5 for three days to mourn the victims of the blasts as well as the fatal air crash last week.

Various local companies have pledged donations for disaster relief, including tech giants Foxconn and Acer.