UPDATE 1-SAfrica coal mine shut, blast injures workers

* All miners rescued from mine - union

* Mine shut for investigations

(Recasts with new detail, mine owners, union comment)

JOHANNESBURG, Aug 14 (Reuters) - An underground explosion on Friday morning at a coal mine owned by Shanduka Coal in South Africa's eastern KwaZulu-Natal province injured three workers and the mine was temporarily shut down, an official said.

The explosion occurred at the Springlake Colliery near the town of Dundee, and investigations as to what caused it were ongoing, Hentie Hoffmann, the chief operating officer of the unlisted Shanduka Coal told Reuters.

Of the three injured, one was badly burnt and was airlifted to a hospital in Johannesburg. About 17 workers were at the section of the mine when the explosion happened and were taken to hospital for medical checks and received treatment for shock.

About 10 would be kept overnight for further treatment.

"At this stage there is no death. One worker suffered bad burns," Hoffmann said. "Coal production at the mine has been halted to allow for investigations."

South Africa has a high rate of work-related mining deaths. Last year 168 workers died in mines. More than 100 miners have been killed in mines so far this year.

It was unclear how many miners were hurt at the mine because the police, Shanduka and unions gave conflicting figures.

Shanduka Coal is owned partly by the private Shanduka Group in which black business magnate and former union leader Cyril Ramaphosa is the main shareholder, Hoffmann said.

The mine -- acquired on July 1 this year from Petmin Ltd. PETJ.J -- produces 40,000 tonnes of coal a month, mostly destined for export to Europe and Brazil, he said. (Reporting by James Macharia; editing by James Jukwey)