Mogadishu - A search operation was under way in Somalia on Thursday for a cargo plane that crash-landed south of Mogadishu and whose crew were taken hostage by the Islamist group al-Shabaab, officials said.
Coming from Nairobi, the plane was carrying cargo for African Union troops in Somalia when it hit the ground in heavy rain on Wednesday.
The plane had been on its way to Ballidogle airport about 100km north-west of Mogadishu.
The massive search operation involved AU military commanders and "Western military experts," said Mohamed Hussein Shine, a spokesperson for the Lower Shebelle administration.
He did not give details on the Western experts. US experts are believed to be present in Somalia to help the government fight al-Shabaab.
It was difficult for the rescuers to locate the plane, because al-Shabaab had covered it with tree branches to confuse search helicopters, Shine said.
Al-Shabaab was believed to have taken the hostages away from the crash site, according to the official.
Officials earlier said the plane carried 12 military personnel. Their nationalities were not clear.
Somali officials said some of them were believed to be US citizens, but the Pentagon denied this.
A Somali aviation official in Mogadishu, who spoke on condition of anonymity, said word of the crash landing had been received from the flight information centre in Nairobi.
The plane, which normally carries out undercover flights for peacekeeping forces in Somalia without prior knowledge of aviation officials in Mogadishu, was unregistered, according to the official.
Another Somali official in Mogadishu, who asked to remain anonymous, said the plane had large amount of US dollars on board.
Ballidogle airport is used by the US government to conduct drone operations in Somalia.