The Islamist militant group Hizbul Islam confirmed Friday that a top commander has been killed outside the Somali capital Mogadishu.
Witnesses say unidentified gunmen opened fire on a car carrying insurgent commander Ahmed Abdurrahman Odawa, killing him and two other people.
A spokesman for Hizbul Islam told VOA his group is investigating who is responsible for the attack.
Tensions have been rising between Hizbul Islam insurgents and the al-Qaida-linked group al-Shabab.
The groups had been working together to battle Somalia's weak transitional government. But they recently fought each other for control of the southern port city of Kismayo, a key source of revenue for the militants.
This week the insurgent groups announced they had agreed to a truce and planned to settle their differences under Islamic law.
Separately, a United Nations delegation visited Mogadishu Friday to discuss humanitarian efforts and the possibility of reopening the U.N. office in Mogadishu.
Somalia has not had a stable central government since 1991.
Al-Shabab and its allies control much of southern Somalia after a nearly three-year war against the Western-backed Somali government.
Some information for this report was provided by AP.