Jordan's prime minister on Sunday said a number of officials had been sacked as he blamed "negligence" for a toxic gas leak that killed at least 13 people.

A tank of chlorine gas fell as it was being loaded by crane onto a ship in Jordan's Red Sea port of Aqaba last Monday, releasing the toxic substance.

At least 13 people, including five Vietnamese nationals, were killed and more than 260 others injured, according to the latest official toll.

An investigation showed "great deficiency and negligence in safety measures for dealing with hazardous materials in the Aqaba port", Prime Minister Bisher al-Khasawneh said during a cabinet meeting.

The director and other officials from the state port operator as well as the head of the maritime authority were sacked, the premier added.

The gas canister's weight far exceeded the maximum load of the crane cable bearing it, said Interior Minister Mazen al-Faraya, who headed the investigation.

"The container weighed about 28,900 tonnes, which is over three times more than the capacity of the cable of 8.6 tonnes, causing it to break," Faraya told a news conference.

A total of "18 containers of chlorine gas were supposed to be loaded onto the ship", he said.

"During the loading of the fifth, the cable broke and the container fell, leading to the gas leak," he added.

Faraya blamed the incident on "recklessness and negligence" at several levels, saying the port company had failed to show leadership.

Jordan's public prosecutor had on Tuesday launched an investigation into the incident, which caused the temporary closure of Aqaba's nearby beaches.

Aqaba is Jordan's only maritime gateway and a transit point for the lion's share of its imports and exports.