Dubai | The death toll from a huge explosion that rocked one of Iran's main ports rose Monday to 46 people killed, authorities said.

Iranian state television offered the toll from the blast at Shahid Rajaei port near Bandar Abbas, citing local officials.

A fire still burned at the site, some two days after the initial explosion Saturday, just as Iran began a third round of negotiations with the United States over its rapidly advancing nuclear program. Over 1,000 people suffered injuries in the blast.

Authorities still haven't offered an explanation for the explosion.

Private security firm Ambrey says the port received missile fuel chemical in March. It was part of a shipment of ammonium perchlorate from China by two vessels to Iran, first reported in January by the Financial Times. The chemical used to make solid propellant for rockets was going to be used to replenish Iran's missile stocks, which had been depleted by its direct attacks on Israel during the war with Hamas in the Gaza Strip.

The Iranian military denied receiving the chemical shipment.

Social media footage of the explosion saw reddish-hued smoke rising from the fire just before the detonation. That suggests a chemical compound being involved in the blast, like in the 2020 Beirut port explosion.