The Somali armed Islamist group al-Shabab has seized a United Nations helicopter, along with about eight people, both passengers and crew, local sources have told the BBC.
The helicopter landed in territory controlled by the group in central Somalia.
Some reports said it had been forced to make an emergency landing, while others said the landing was a mistake.
Al-Shabab controls large parts of southern and central Somalia.
The group is affiliated to al-Qaeda and has waged a brutal insurgency for nearly 20 years.
The seizure of the helicopter was confirmed to the BBC by Galmudug region Security Minister Mohamed Abdi Adan.
Several foreigners and two locals were on the helicopter, Somali military official Major Hassan Ali told Reuters news agency.
"It was also carrying medical supplies and it was supposed to transport injured soldiers from Galgudud region," he was quoted as saying.
The helicopter was heading to Wisil town near the frontlines of an offensive against al-Shabab by government forces when it landed.
The UN has not yet commented.
The Somali government has in recent months intensified its fight against the al-Qaeda-linked group.