Firefighters have brought under control a blaze at Iran's main port, following a deadly explosion blamed on negligence, authorities in the Islamic republic said.

The death toll from a powerful explosion at Iran's biggest port has risen to at least 40, with more than 1,200 people injured, state media reported on Sunday.

Drone footage has captured the damage at an Iranian port after a deadly explosion rocked the facility. The death toll has now risen to 70 people after the Saturday blast at the port of Shahid Rajaee in Bandar Abbas, and an investigative committee has blamed the blast on safety failures, according to Iranian state-run media outlets.