A number of British women travelling with an aid convoy are believed to have been raped in Libya.
Pro-government militiamen are suspected of attacking three of the activists in the eastern city of Benghazi, the country's deputy prime minister Awsad al-Barassi said.
The women were reportedly kidnapped on Tuesday and later released.
Mr al-Barassi told a Libyan television channel he had met the women and they were in "very bad shape".
A Foreign Office spokesman said: "We are aware of an incident in Libya involving a number of British nationals who were part of an aid convoy. We are providing consular assistance."
The overland convoy left Britain on February 25 but was stuck for days along the Libyan-Egyptian border after Egyptian border guards refused to let them cross.
Mr al-Barassi told Libya al-Hurra TV that two of the women are sisters and their father witnessed the rape.
Their 10-vehicle convoy carrying medical supplies was named "Mavi Marmara" in honour of a ship involved in a 2010 deadly flotilla incident, according to Huseyin Oruc of IHH, a Turkish humanitarian relief organisation.
IHH was the group that helped organise the international flotilla that was attacked on May 31, 2010. Israeli commandos stormed the Mavi Marmara while stopping the flotilla that was trying to breach an Israeli blockade of Gaza. Eight Turks and a Turkish-American were killed, and dozens of activists and seven Israeli soldiers were wounded.
IHH mediated the release of the kidnapped women and men after they were contacted by the convoy's organisers and asked for help. The man and his daughters are scheduled to return to Britain on Friday, he said.