Updated

A militant group claimed in a Web posting Thursday that two Italian women taken hostage in Iraq had been killed, a day after another group made a similar statement. Neither claim could be immediately verified.

Italy cast doubt on the claims, saying the communiques could be part of a terrorism campaign through the media.

"Italian intelligence services have confirmed ... that they believe these claims to be completely unreliable," Enzo Bianco, a lawmaker who heads the parliamentary commission overseeing secret services, told Italian news agencies.

"I urge caution because this will be a long and complicated story. A war through the media is under way," Bianco added.

The new posting about the purported beheadings of Simona Pari (search) and Simona Torretta (search) appeared on a little-known Web site and was signed by a group calling itself the Supporters of al-Zawahri. That group's name refers to Ayman al-Zawahri (search), a deputy of Al Qaeda leader Usama bin Laden.

That same group was the first to claim responsibility for the Sept. 7 capture of the two women.

A second militant group, the Islamic Jihad Organization in Iraq, also claimed to be holding the two women. On Wednesday, a purported statement from the group had said the two aid workers were killed because Italy had ignored demand to withdraw troops from Iraq.

The latest statement from the other group promised that video of the slayings would be released.

"The heads of the two criminal agents of Italian intelligence, Simona Pari and Simona Toretta have been chopped off by knife without pity or mercy," said the claim. "The video of cutting off the heads of the two Italian hostages will be issued soon."

The statements were impossible to verify immediately.

Pari and Torretta, both 29, were seized from their Baghdad offices by armed militants on Sept. 7. They worked for "Un Ponte Per ..." ("A Bridge to ...") and were involved in school and water projects in Iraq.

The Supporters of al-Zawahri first claimed to have kidnapped the women on Sept. 10, three days after they were seized in their Baghdad office. In an Internet statement at the time, the group accused the Italian government of helping U.S. soldiers abuse Iraqi prisoners and gave Italy 24 hours to pledge to release all Muslim women held in Iraqi prisons.

In its posting Thursday, the group defended the beheadings by saying they were a response to numerous alleged events apart from the failure to release all Muslim women in Iraqi prisons.

The group accused the Italian troops of committing "brutal bloody massacres" in the southern Iraqi city of Nassiriyah and accused "Crusader Zionist troops in Iraq" of raping Muslim women and men. It also referred to Italian Prime Minister Silvio Berlusconi's (search) remark that Western civilization was superior to Islamic civilization, calling it a "humiliation." Berlusconi had apologized for the remark.

The demand that female prisoners be freed was also made by the Iraqi insurgents who kidnapped two Americans and a Briton last week. The Americans were beheaded this week after the U.S. forces refused to free two Iraqi women in their custody and militants said the third was next.

The demands appear to be a militant attempt to tap into widespread disgust in the Arab world over the U.S. abuse of Iraqi men at Abu Ghraib prison (search) as well as strong feelings about female honor in the Muslim world.