A white cloud covers the area where a large gas leak occurred in western Thessaloniki yesterday. An emergency action plan for industrial accidents was put into effect by authorities for the first time since 1986.

A massive fuel leak from a pipeline in a factory located in western Thessaloniki was contained yesterday after releasing 50 tons of natural gas into the air, authorities said, but there were no reports of injuries.

The leak occurred at 10.30 a.m. after a repair crew using digging equipment accidentally knocked a hole in the pipeline belonging to a factory owned by petrol refiner Hellenic Petroleum in the Kalohori area.

Authorities launched a four-hour emergency action plan and evacuated the area within a 2.5-kilometer radius of the leaking pipeline, fearing that it could catch fire.

A white cloud spread from the point where the leak had sprung, giving off a strong odor, according to witnesses.

Power to the surrounding area, which accommodates tens of small factories and industrial plants, was also cut off.

Authorities said that favorable weather, with light winds and damp conditions, helped prevent the gas from spreading further afield.

A prosecutor has ordered an investigation into the causes of the accident.

Experts eased concerns yesterday about the impact on the environment from the gas, which consists of 80 percent butane and 20 percent propane.

“There will be no consequences for the environment from the gas leak in western Thessaloniki’s residential areas,” said Constantini Constantinou-Samara, a chemistry professor at the northern city’s Aristotle University.

“A direct threat to the lives of residents and the environment would have arisen had the leaking gas caught fire,” Samara added.