A fire has broken out at an oil refinery in Spain sending thick smoke billowing into the sky that could be seen for miles.

The fire reportedly started at the petrochemical plant in San Roque, Andalusia, this afternoon at around 3.10pm local time.

A plume of smoke was seen rising over the Bay of Gibraltar as a result of the blaze from the plastics producing premises owned by Indorama.

A state of emergency was declared by authorities as the plant contains highly flammable products, according to local media.

Houses within a 30 miles (50km) radius of the plant have been ordered to be evacuated due to the potentially toxic fumes.

Cars were left covered in a ‘black ash’ as the ‘very dangerous chemicals are burning’, Spanish media reported.

Algeciras city council activated its emergency response plan and neighbouring authorities are expected to follow suit.

Juan Carlos Ruiz Boix, the mayor of San Roque, told the Gibraltar Chronicle emergency services were finding it hard to extinguish the blaze.

Source: dailymail