Colombia rescuers dig for dead after mine blast

* Mass burials continue after huge mine blast

* Rescuers struggle with gas build-ups to reach bodies

BOGOTA, June 21 (Reuters) - Colombian rescuers on Monday vowed to pull out the remaining bodies from a coal mine so that distraught relatives can give them a proper burial after an explosion killed some 70 miners.

Emergency workers, clad in plastic suits and oxygen masks to withstand the stench of decaying bodies, have retrieved at least 30 bodies and believe another 40 are still in the mine, five days after one of Colombia's worst mining disasters.

"We are working as hard as possible so they can give a proper Christian burial to all of those who lost their lives down in the mine," said Dario Vieira, head of a rescue team struggling with gas build-ups in the mine to recover bodies.

"The president has ordered us to retrieve all the bodies and that's what we will do," he told Reuters by telephone.

President Alvaro Uribe met relatives of the workers at the Carbones San Fernando mine during the weekend in Amaga, a rural town ringed by coal mines that have claimed many lives in the past. Coal mining is one of the world's most dangerous jobs, especially in China where explosions and accidents are common.

Sobbing relatives were still burying dead miners in outdoor funerals on Monday in Amaga, where crowds carried coffins on their shoulders and gathered outside a town hall converted into a makeshift morgue.

The blast at the mine in the northwestern Antioquia province on Wednesday highlights mining regulations in a country where the industry ranges from multinationals digging coal from massive deposits to wildcat operations supplying the local market.

The small San Fernando mine was far from key coal operations of Drummond and Glencore and the blast is not expected to hurt output in the world's No. 5 coal exporter.

Colombia's energy and mining industries have boomed under Uribe, who has driven back leftist rebels fighting Latin America's oldest insurgency. His former defense minister, Juan Manuel Santos, on Sunday won an election to succeed him.

Reporting by Alonso Soto; Editing by Patrick Markey and Bill Trott