Witnesses in Hobyo, in the Mudug region of Somalia, said fighting broke out when a group of pirates tried to capture another pirate gang, Shabelle Media Network said.
"We woke up this morning hearing the barrage of bullets and sounds of artillery fire exchanging between two groups of Somali pirates," one resident told Shabelle.
Officials said calm had been restored in Hobyo, believed to be a pirate hideout.
Somali pirates have attacked hundreds of ships traveling in the Arabian Sea and Indian Ocean.
Notable deaths of 2014 [PHOTOS]