A deadline set by Islamist militants holding two Austrian tourists expires Sunday. Al-Qaida in Islamic North Africa has given authorities until midnight (2300 GMT) to release some of its members in jails in Tunisia and Algeria. The group is reportedly also seeking a ransom. Wolfgang Ebner and Andrea Kloiber disappeared while on vacation in Tunisia last month. The group holding them has said Austria, Tunisia and Algeria would be responsible for their lives after the deadline expires, and has warned that any attempt to free them would result in their immediate execution. Austrian officials have been working intensely their diplomatic contacts to free the couple, whose exact location remains unclear. Media reports have placed them in Mali; Austrian envoy Anton Prohaska has been in the country for some time. Joerg Haider, the governor of the southern Austrian province of Carinthia, said Saturday that Libyan leader Moammar Gadhafi's son, Saif, told him that he was "very optimistic" after intensive negotiations with the militants. On Sunday, in comments carried by the Austria Press Agency, Haider said the endeavor was a personal, secret initiative by Saif that had not been prearranged with the foreign ministry. An initial March 16 ultimatum set by the hostage-takers was extended by a week just hours before it expired. Foreign Ministry spokesman Peter Launsky-Tieffenthal said the crisis management team handling the matter met earlier Sunday and that a further session was planned for the afternoon. The group consists of officials from the chancellory, as well as from the country's foreign, interior and defense ministries. Launsky-Tieffenthal declined to specify whether the negotiations had reached a decisive phase but stressed that efforts to secure the release of the couple were continuing at full force throughout the region. Austrian authorities have kept details to a minimum so as not to jeopardize their attempts or endanger the lives of the hostages.