Three Italian women taken hostage by Yemeni tribesmen on Sunday refused to be released, instead insisting on returning to their two male companions who were still held captive, local government sources said.
The kidnapping of the five tourists occurred just one day after a German family of five, including a retired top diplomat, were freed and was the fourth abduction of foreigners in the country within the space of three months.
"We have received a report of the kidnapping of five Italians ... in Sirwa in the region of Marib," 170km east of Sanaa, a security official said.
A local government official said that three females were released shortly after and handed over to the local government in Marib, while the two men remained captive.
He said that negotiations including tribal chiefs and local officials had started to secure the release of the remaining captives.
But the freed women refused to be released without their companions and demanded to rejoin the other two in captivity, a local government source said.
"After they [the three women] were handed over to the local government, they refused the initiative to release them and insisted on remaining with the other two hostages," the source said.
"They demanded to return [to the hideout] after arriving in the office of the local government," he added, saying that the trio had now rejoined their companions.
Italy's foreign ministry confirmed the kidnapping of Italian citizens in Yemen, saying it knew their identities but without giving further details.
A later statement said the ministry could not confirm the release of the three women.
A tribal source said that the captors belong to the Al al-Zayidi clan, which belongs to the Jahem tribe, and that they are demanding the release of eight members of their clan imprisoned for a tribal vendetta.
"The captors are demanding the release of the sons of Naji Abad Zayidi and his brother Saleh, who was extradited from the United Arab Emirates," the source, who belongs also to the Zayidi clan, said.
"They were arrested following the murder of a member of Al al-Qeiri clan in December 2004, as a result of dispute ... over a car deal," he added.
As the murderer escaped justice, the Yemeni authorities arrested his eight relatives, he claimed.
He said that the captives were led along with their Yemeni driver to a rough mountainous area which belongs to the Jahem tribe.
A number of Italians have been captured in the past by tribesmen.
A former German top diplomat and his family who were taken hostage by Yemeni tribesmen in the eastern province of Shabwa were freed on Saturday after security forces laid siege to the kidnappers' hideout.
Juergen Chrobog -- a former ambassador and foreign ministry number two -- and his wife and three sons were freed while their four captors arrested.
Yemeni President Ali Abdullah Saleh late on Sunday dismissed the governors of Marib and Shabwa, in a move apparently related to the recurring abductions in the tribal regions.
Last month, two Austrian tourists were held hostage for three days also in the Marib region. In November, two Swiss holidaymakers were briefly held by tribesmen in the same area.
Nearly all of the kidnappings in Yemen have been carried out by tribesmen seeking to put pressure on the central government and the hostages have generally been released unharmed.