Al-Qaida militants on Thursday seized a seaport in Yemen's southern port city of Abyan after days of fierce battles with the army forces, local officials told Xinhua.

Units of the army forces tried to repel attacks by al-Qaida militants and prevent their advance towards a small seaport in Zinjibar city in Abyan, but al-Qaida militants forced the army by using heavy fire to withdraw from controlling the seaport, a military official said, who asked to remain anonymous.

The militants continued their advance in order to topple the 25 Mechanics military camp, the official added.

Heavy fighting between the army forces and groups of al-Qaida militants has erupted since Tuesday night in the eastern outskirts of Zinjibar city, according to a local security official.

Al-Qaida militants tries to control the small seaport in the city in order to bring in more foreign fighters to Yemen, the official told Xinhua.

Al-Qaida affiliates in Saudi Arabia and Yemen officially merged in January 2009 and formed al-Qaida in the Arabian Peninsula (AQAP) . The worsening internal conditions in Yemen created a haven for al-Qaida to plot, plan and mount several domestic attacks on police stations and government buildings in Yemen's main provinces during the past two years.