Somalia's semi-autonomous Puntland region has announced an investigation into a recent increase in piracy activity off the East African country's coast.

Somali pirates have reportedly seized a Tanzanian-flagged commercial vessel in the Gulf of Aden, within Yemeni territorial waters. The incident occurred last week, according to residents of the semi-autonomous Puntland region.

Puntland forces, supported by the US, are fighting the Islamic State in the mountains of Somalia, aiming to dislodge the group from its last stronghold which serves as a global hub for IS operations.

Puntland forces have reportedly taken control of a camp in Galkayo, Somalia, following intense clashes that led to the retreat of rival federal-aligned forces.

Qatar has condemned the hijacking of an oil tanker carrying Egyptian sailors, which was reportedly seized in Yemeni territorial waters and taken toward Somali waters near the Puntland region.

A US military delegation visited Somalia's Puntland region to expand its strategic presence on the coast, as the conflict in Yemen continues to simmer.

The Islamic State group has reportedly made Somalia its new front line in Africa, settling largely undisturbed in a mountainous area of nearly 5,000 square kilometers in the Puntland region after their defeats in Iraq and Syria.