* Islamists say will fight till last man
* Ethiopia to send help only with international mandate
By Ibrahim Mohamed
MOGADISHU, June 21 (Reuters) - Somalia’s hardline al Shaabab Islamists will fight any foreign troops that come to the aid of the Horn of African government, a spokesman for the insurgent group said on Sunday.
Somali parliament speaker Sheikh Aden Mohamed Madobe on Saturday called upon neighbouring countries such as Djibouti, Kenya and Ethiopia to send military help to ward off a raging rebellion.
The African Union already has 4,300 peacekeepers in Somalia, but they are under constant attack by the Islamists that want to dislodge the government and impose a strict form of sharia, Islamic law.
"We tell our enemy that we do not fear any invasion from outside. We forced Ethiopia to withdraw from Somalia early this year and we shall do the same again," al Shabaab’s Sheikh Ali Mohamud Rage told a press conference.
"We, the Somali young mujahideen, shall fight against any troops deployed here to help the government until our last holy fighter passes away. This is a clear signal that the so called government established by the enemy had totally failed."
Ethiopia, which had troops in Somalia for two years but withdrew them in January, said on Saturday it would only send in help under a mandate from the international community.
But residents close to the border with Ethiopia say their neighbour already has troops in their country.
Kenya said on Friday it would not sit by and allow the situation in its neighbour to deteriorate further because it would destabilise the region.
Countries in the region as well as Western nations fear that if the chaos continues in Somalia, groups with links to al Qaeda will become entrenched and threaten the stability of neighbouring countries.
The U.S. has al Shaabab on its list of terror organisations.
"God will help us to overcome all enemies and we believe we shall defeat them. We are not worried about their quantity and whatever weapons they have," Rage said.
His group has intensified attacks against the government since May and killed two legislators this week, including the security minister.
Some 300 people have been killed since May 7, in fighting residents say is the worst for years.
The Horn of Africa country has experienced violence for close to two decades. (Writing by Helen Nyambura-Mwaura; Editing by Matthew Jones)