Both men were seen giving their names and addresses in the video

The announcement by the president's office came after a group claiming to be al-Qaeda in Iraq posted an internet message saying it had killed the pair.

Top envoy Ali Balarousi and colleague Azzedin Belkadi were seized by armed gunmen in the capital last Thursday.

Their deaths follow the killing of Egypt's ambassador-designate, which insurgents say they carried out.

Officials say insurgents have launched attacks on diplomats to try to dissuade Arab countries from raising the level of their diplomatic representation.

'Monstrous act'

Algerian radio interrupted its programming to report the killings.

President Abdelaziz Bouteflika called it a monstrous act.

"In the most cowardly fashion, the kidnappers have... carried out their vile threats," he said in a statement.

Earlier on Wednesday, a group claiming to be al-Qaeda in Iraq said it had killed the Algerians because of their government's support for the US.

"Iraq will not be safe for God's enemies. Haven't we warned you against allying yourselves with America," the group said.

The two Algerians had appeared in a video made public on Tuesday.

An earlier internet posting from the group, which is thought to be led by Jordanian-born militant Abu Musab al-Zarqawi, warned that the two men would be killed after being tried in an "al-Qaeda court".

Algeria withdrew all its diplomats from Iraq following last week's abductions.

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