The group, calling itself al-Jihad Brigades of Iraq, urged citizens to stop cooperating with the new interim ruling council and the occupation administration.
“We swear to avenge those who have been killed. Greetings to our fellow mujahidiin in Anbar, Salah al-Din and Dialla,” said the first of three masked speakers in his opening statement.
Anbar is west of the capital, Baghdad, and Salah al-Din and Dialla are in the north west and north east of the country respectively.
“We are ready to sacrifice ourselves for the sake of the religion and the nation and to pursue a guerrilla warfare to liberate Iraq,” he added.
Call for war
The second speaker claimed the Interim Council is stealing Iraqi wealth.
He urged all citizens to stop dealing with institutions backed by the US “in order to preserve our religion and our honour, they are spreading corruption and have killed our people.”
The tape said those Iraqis aiding occupation forces should be treated as spies and traitors and called on all nationals to engage in a guerrilla warfare to liberate Iraq.
Supposedly recorded on Monday, a picture of the deposed president Saddam Hussein was seen on the video tape and his name was mentioned by the last of the three statements.
"...preserve our religion and our honour, they are spreading corruption and have killed our people."
Anonymous speaker -
Al-Jihad Brigade of Iraq
“Stop chasing our fellow brothers from the former regime. We will kill the spies and those who co-operate with them. God is great, death to America.”
The tape was released at the same as both an American soldier and his Iraqi translator were blown up in the capital.
The US soldier and the interpreter were killed in an attack in Baghdad, according to a US military spokesman.
At 06:30 GMT, an improvised bomb went off destroying an American Humvee military vehicle. Witnesses told journalists it blew up as it was moving along the street and then came under small arms fire.
The spokesman would not name the two casualties, only confirming the soldier was from the First Armored Division.
The fatality brings the official published number of US soldiers killed in action since the beginning of the invasion on 20 March to 153, though over forty have died in accidents.
There are no official figures for the number of Iraqi civilians that have died since invasion forces took control of Iraq in early April, though the number is known to be over six thousand.