Saif al-Islam, son of the late former Libyan leader Muammar Gaddafi, sits after his capture, with his fingers wrapped in bandages and his legs covered with a blanket, at an undisclosed location, in this photograph aired on Free Libya TV on November 19, 2011. [Photo/Agencies]

TRIPOLI, Libya — Muammar Gadhafi's son Seif al-Islam — the only wanted member of the ousted ruling family to remain at large — was captured as he traveled with aides in a convoy in Libya's southern desert, Libyan officials said Saturday. Thunderous celebratory gunfire shook the Libyan capital as the news spread.

A spokesman for the Libyan fighters who captured him said Seif al-Islam, who has been charged by the International Criminal Court for crimes against humanity, was detained about 30 miles (50 kilometers) west of the town of Obari with two aides as he was trying to flee to neighboring Niger. But the country's acting justice minister later said the convoy's destination was not confirmed.

His capture just over a month after his father was killed leaves only former intelligence chief Abdullah al-Senoussi wanted by the ICC, which indicted the three men in June for unleashing a campaign of murder and torture to suppress the uprising against  Gadhafi that broke out in mid-February.

Libyan TV posted a photo purportedly of Seif al-Islam in custody. He is sitting by a bed and holding up three bandaged fingers as a guard looks on. International rights groups urged the Libyans to respect his human rights.

"Seif must face justice. Whether it's in Libya or in The Hague, he should face justice. We have to coordinate together with the Libyan authorities," ICC Prosecutor Luis Moreno Ocampo said in a telephone interview.

Mohammed al-Alagi, the National Transitional Council's justice minister, told The Associated Press that Seif al-Islam was detained deep in Libya's desert Friday night by revolutionary forces from the mountain town of Zintan who had been tracking him for days.

Seif al-Islam was being held in Zintan but would be transported to Tripoli soon, according to al-Alagi.

A spokesman for the Zintan brigades, Bashir al-Tlayeb, who first announced the capture at a press conference in Tripoli, said the NTC, which took over governing the country after Gadhafi was ousted, would decide where Seif al-Islam would be tried.

"Seif al-Islam was caught with two aides who were trying to smuggle him into Niger," al-Tlayeb said, adding that he had no information about al-Senoussi's whereabouts.

The justice minister, however, said Seif al-Islam was captured closer to the Algerian border and the convoy's destination was not known.