Somali insurgent group al-Shabab says it will fight rival Islamists for control of a strategic town.
Witnesses say both al-Shabab and Hizbul Islam have positioned fighters on the streets of Kismayo, a port city in southern Somalia. Hundreds of residents have fled the area, fearing bloodshed.
The groups jointly captured Kismayo in August 2008, and ran it together until last week, when al-Shabab named its own local governing council.
A local militia leader rejected the move, and Hizbul Islam sent hundreds of fighters into the town on Saturday.
An al-Shabab spokesman, Sheikh Hassan Yaqub, told reporters Wednesday that al-Shabab has declared a "holy war" on Hizbul Islam. He also accused the rival group of promoting "un-Islamic" practices.
The port is an important source of revenue for the militant groups.
Al-Shabab and Hizbul Islam are usually considered allies, and launched a joint offensive against the Somali government in May. However, the groups are believed to have different religious and political agendas.
Al-Shabab is known for enforcing a strict interpretation of Islamic law in the areas it controls. On Monday, the group publicly executed two men it accused of spying for foreign governments, and flogged another person charged with making counterfeit U.S. dollars.
Some information for this report was provided by Reuters.