MOGADISHU, Jan. 1 (Xinhua) -- Somalia's hardline Islamist rebel group of Al Shabaab on Friday vowed it will send fighters to fight along side radical insurgent groups in Yemen across the Gulf of Aden north of war torn Somalia.

The group, which controls much of south and center of Somalia, paraded hundreds of newly-trained Islamist fighters at a one of the group's base on the northeastern part of Mogadishu.

"We will help our brothers in Yemen. We will cross the sea between us and fight along side with you against the enemy of Allah," sheikh Muqtar Robow Abu Mansuur, a prominent Al Shabaab official, told hundreds of heavily armed newly trained militias who chanted "God is great" in Arabic.

Yemen, which borders Somalia just across the Gulf of Aden, has been fighting Islamist rebels opposed to the government there.

Al Shabaab, which wages relentless attacks on Somali government targets, said it was prepared to counter a possible offensive by the Somali government forces and African Union peacekeepers based in Mogadishu.

The groups' officials urged its militias to "destroy" the United Nations, the International Court of Justice in the Hague and the international community as a whole accusing them of being "anti-Islam".

The radical movement, the largest and most powerful rebel group in Somalia, which is considered a terrorist entity by the Somali government and several other countries, sees the international institutions as tools used by the West against Islam.

The Somali government which controls only parts of Mogadishu under the protection of some 5,000 African Union peacekeeping forces, enjoys international legitimacy but is fighting for its survival and is widely believed to be planning for a major offensive against the rebels in Mogadishu.