The death toll from a massive explosion at Iran's largest commercial port has risen to 28, Red Crescent chief Pirhossein Koolivand said Sunday, updating earlier figures reported by state media.

"Unfortunately, 28 people have so far died," Koolivand said in a video published on the Iranian government's official website, adding that some of the more than 1,000 injured in the Shahid Rajaee Port blast on Saturday had been transferred to the capital, Tehran, for treatment.

Iran's Defense Ministry said Sunday there was no military cargo at the site of the explosion.

"There has been no imported or exported cargo for military fuel or military use in the area of the fire incident and Shahid Rajaee Port," Reza Talaei-Nik, a spokesperson for the ministry, told state television.