The death toll from a powerful explosion at Iran's biggest port of Bandar Abbas has risen to at least 25 dead, with more than 700 people injured, state media reported on Sunday, as firefighters worked to fully extinguish the fire.

At least 25 people were killed and hundreds of others were injured in a massive blast that rocked the Iranian port city of Bandar Abbas on Saturday.

Social media videos show a huge plume of black smoke and a ball of fire rising from the area of the explosion.