Italy's Foreign Minister Franco Frattini Sunday said he will travel to the Middle East to push ahead with efforts aimed at securing the release of two female aid workers taken hostage in Iraq. The decision followed an ultimatum published on an Islamist Web site demanding Italy withdraw its troops from Iraq within 24 hours.

Italian authorities have been working to obtain the release of two of its aid workers kidnapped Tuesday from their office in central Baghdad. Junior Foreign Minister Margherita Boniver was immediately dispatched to the Middle East trying to secure Arab support for the liberation of the two women.

So far, no video or information on the condition of the hostages has been made available by their captors. But two messages have appeared on the Internet.

The first on Friday, from an unknown group calling itself Ansar al-Zawahiri, had given the Italian government 24 hours to promise to release Muslim women prisoners in Iraq in return for information about the two Italian volunteers.

The second, which appeared on a Web site early Sunday, was signed by the Islamic Jihad Organization in Iraq. It said the two women would be killed unless Italy withdraws its troops from Iraq within 24 hours.

While not prepared to give in to the demands, Italy wants to avoid taking any unnecessary chances. The government has already been criticized for failing to do enough to obtain the release of hostages taken in Iraq.

Two Italian hostages, a journalist and a security official, have already been killed by their captors.

In a statement Sunday evening, the Italian Foreign Ministry said that Mr. Frattini would undertake a mission to the Gulf region in the upcoming hours as part of the government's political efforts to secure the liberation of the hostages.

The statement added that Mr. Frattini would be holding a series of meetings with civil and religious authorities, starting in Kuwait. He would also be renewing "calls for solidarity and respect for the lives of innocent civilians, working generously for the Iraqi population".

Italians, many of whom opposed the U.S.-led Iraq war, were shocked by the kidnapping of the two aid workers. Their abduction stirred strong emotions because they were both involved in helping child victims of the Iraq conflict. Protest marches and calls for their release have been made all over Italy.