Sparks from an electric chaser that came in contact with sewage gases caused an explosion in a factory under construction in Bulebel, yesterday.

Nobody was injured at Solea Pharma Ltd, a generics pharmaceutical company set to open for business in two months' time, employing about 15 people.

The incident happened at about 10.45 a.m. at the Bulebel industrial estate. The police said the explosion was a small one and did not cause much damage.

According to Solea plant manager Claude Vella Bonanno, sewage gases that had built up in drain pipes caused the explosion that was triggered by sparks from an electric chaser.

The company is equipped with an underground hazardous waste reserve, where any leaked gases gather.

When the explosion took place, a tarmac roller parked on top tumbled into the hole in the ground, Mr Vella Bonanno said, adding that, luckily, the vehicle was not being used.

Efforts were being made in the afternoon to try and retrieve the vehicle but workers had to wait for a surveyor before this could be done.

The explosion was barely heard by those working in the company's offices, Mr Vella Bonanno said. However, a fire broke out and personnel of the Civil Protection Department had to be called to extinguish it.

Solea Pharma is part of the Gadea Pharmaceutical Group, an independent Spanish group of affiliated companies dedicated to the technical development services, production and marketing of active pharmaceutical ingredients.