Updated

A previously unknown group claimed responsibility for the deadly bombing of the U.N. headquarters in Baghdad, an Arab television station reported Thursday.

The claim from a group calling itself the Armed Vanguards of the Second Muhammad Army (search) came in a two-page typewritten, Arabic statement shown on the Al-Arabiya station, which also faxed a copy to The Associated Press.

The station said it received the statement Thursday but did not say how or where. There was no immediate way to confirm its authenticity.

"We, the Armed Vanguards of the Second Muhammad Army, claim responsibility for the bombing of the U.N. headquarters. We say it proudly that we did not hesitate for one moment to kill Crusader blood," the statement said.

Tuesday's attack killed at least 23 people and wounded at least 100.

The statement pledged "to continue fighting every foreigner [in Iraq] and to carry out similar operations." It threatened U.S. forces and Arabs and Muslims who aid them and said Arab countries should not send troops to Iraq to serve in an international peacekeeping force.

Several self-proclaimed fighting forces have appeared in the Arab media in recent months, proclaiming responsibility for attacks on coalition and civilian targets in Iraq.

However, it is difficult to determine whether any of the groups have staged attacks or even exist beyond sending videotapes and written statements.

Thursday's statement also criticized the United Nations (search), saying it failed to stop the U.S.-led invasion. Many in Iraq and elsewhere had questioned why the United Nations, which has provided humanitarian aid to Iraqis and pushed for the U.S.-led coalition to quickly hand power to Iraqis, would be a target.

Muslim militant groups such as Al Qaeda have expressed hostility toward the world body, accusing it of lending its legitimacy to encroachment on Palestinian lands and attempts to contain Iraq.