Haider al-Abadi, Iraq's prime minister, has said the burning of a warehouse in Baghdad where ballot boxes from last month's disputed parliamentary elections were kept was part of a plot to sabotage the country's democratic process.

His comments on Sunday were the most high-profile indication that the fire in the Iraqi capital was deliberate.

"Burning election warehouses ... is a plot to harm the nation and its democracy," Abadi, whose coalition faltered in the polls by finishing third, said in a statement on Sunday.

"We will take all necessary measures and strike with an iron fist all who undermine the security of the nation and its citizens," he added.

Last week, parliament passed a law for a recount of 11 million votes, following allegations of fraud during the May 12 elections.

The cause of the blaze was not immediately known but a local official said that boxes, part of a manual recount of votes from the al-Rusafa district in eastern Baghdad, had all been scorched.

"I can tell you all the boxes and papers have burned," Mohammed al-Rabeei, a Baghdad province council member, said.

However, an interior ministry spokesman said the fire had destroyed some documents and equipment but first responders on the site were trying to prevent it from spreading to ballot boxes.

The warehouse is one of four at the site, said Major General Saad Maan, and contained documents and electronic equipment.

"It is possible there were also some ballot boxes in the warehouse that caught fire, but most of the important boxes are in the three warehouses where the fire has been controlled," he said.

Prior to Abadi's remarks, Iraq's outgoing parliament speaker Salim al-Jabouri said that the fire was intentional and called for a repeat of the election.

"The crime of burning ballot box storage warehouses in the Rusafa area is a deliberate act, a planned crime, aimed at hiding instances of fraud and manipulation of votes, lying to the Iraqi people and changing their will and choices,” Jabouri said in a statement.

"We call for the election to be repeated,” added Jabouri, who lost his seat in the election. He called for those responsible to be brought to justice by the security forces.

Kazem al-Shammari, a spokesman for the Sunni Wataniya alliance, which won 21 seats, was quoted as saying by al-Araby al-Jadeed that "there was no such incident in all previous election cycles, and the fire coincides with the decision to manually re-count the ballot boxes.

"This indicates a lot of manipulation and forgery, so the forgers sought to hide the crime by burning the boxes.”

Adel Nouri, a member of the Iraqi Parliamentary Integrity Commission, also alleged that the ballot boxes were deliberately set on fire.

"The criminals manipulated the results of the elections because they know that the results that were announced are not true, so they burned the ballot boxes.”

"This crime is not an ordinary crime and not a passing incident, but a major crime and a great betrayal of the country.”

He called on al-Abadi and the responsible authorities to "open an urgent investigation to catch the perpetrators and determine the cause, so as to know who had committed this crime.”

Agencies