More than 10 other people were hospitalised after drinking the water in Masuubiye near the south-western city of Baidoa, regional senior official Hassan Hussein Elay said.

Elay accused the militant Islamist group al-Shabaab of poisoning the well.

"Al-Shabaab poisoned the waterhole to prevent government soldiers from drinking water there," he said, without providing details.

Al-Shabaab has reportedly poisoned wells in the past. It was not immediately known if any soldiers had died in the latest incident.

There was no comment from al-Shabaab, which has fought the Somali government for a decade in an attempt to establish an Islamic fundamentalist state.