Anxious Search For Missing After Deadly Mexico Blast

Coatzacoalcos, Mexico: Mexican authorities today pursued their search for eight people missing after a petrochemical plant explosion that killed at least 24 and spewed a toxic cloud into the air.

Wednesday's blast sent workers flying through the air and shattered the windows of homes and businesses, sparking panic in the town of Coatzacoalcos, in the eastern state of Veracruz.

The number of deaths could rise further as 136 people were injured, 13 of them critically.

The inside of the blast site was initially too hot for rescue workers to enter, but after hosing it down with water, they finally managed to get inside on Thursday and look for the missing.

Hundreds of anguished relatives have been nervously awaiting news of their loved ones, scuffling on Thursday with soldiers who had set up a security cordon around the plant.

Soldiers eventually began allowing small groups of family members into the facility, which is co-owned by state oil company Pemex and a private company, Mexichem.

The plant was a cataclysmic scene of deformed metal structures, scorched holding tanks and blown-out office windows through which overturned furniture could be seen.

A powerful chemical smell wafted from the facility, causing some soldiers and locals to don face masks.

President Enrique Pena Nieto sent his condolences to victims' families and visited the site Thursday afternoon.

A blast at the same plant 25 years ago killed at least six people, although local media insist the number is much higher.

Pemex chief executive Jose Antonio Gonzalez Anaya said Wednesday's explosion was caused by a gas leak.

The plant, known as Petroquimica Mexicana de Vinilo (PMV), "uses flammable materials like chlorine and ethanol but we do not know the cause of the leak," he told Televisa television.

A worker who survived the explosion told journalists some 300 employees were on site when the blast occurred.

"I was out back when the first explosion came. We saw the windows collapse, the iron bars crumple, because (the facilities) are extremely old," he said.

"When the second explosion happened, I saw bodies fly off the scaffolding."

An employee of a contractor at the site, Jose Antonio Galicia, said the plant had been registering leaks for weeks.

Warning To Stay Home

The release of toxic columns of black smoke alarmed locals as officials initially evacuated 2,000 people and warned other residents to stay indoors.

But Mexican authorities and Pemex officials said Thursday the cloud posed no threat to the population.

Chemistry professor Benjamin Ruiz Loyola said the public health risk posed by the chemicals would only reach a minimum level after 36 to 48 hours -- this morning or afternoon.

"It is recommended to remain at home" after such an explosion, said Ruiz, a professor at the National Autonomous University of Mexico.

But if people take precautions, "there are no serious health risks," he said.

Pemex has had to deal with several deadly accidents at its land-based and offshore facilities in recent years.

Even its headquarters -- a skyscraper in the heart of Mexico City -- was hit in January 2013 by a blast caused by a gas buildup, killing 37 people.

Accidents have hit several oil rigs in the Gulf of Mexico, while fires have erupted in pipelines after fuel thieves punctured them.

Pemex provides one-fifth of the Mexican government's revenue but has posted huge losses amid falling production and oil prices.

The government has implemented a sweeping reform of the energy sector which opens it to foreign investors for the first time in decades and partly aims to help modernize aging infrastructure.