- Pro-government militia clashes with rebels
* Fifty people injured
By Abdi Guled and Abdi Sheikh
MOGADISHU, June 2 (Reuters) - Fighting in two central Somali towns left least 24 people dead and 50 wounded as rebels clashed with a pro-government militia, a rights group said on Wednesday.
The moderate Ahlu Sunna Waljamaca group that is aligned with President Sheikh Sharif Ahmed's weak U.N.-backed administration fought with al Shabaab insurgents in Marergur and Gadon towns in the Galgadud region on Tuesday.
"At least 24 people died and 50 more were wounded, mostly combatants, in the long hours of fighting," said Ali Yasin Gedi, vice chairman of the Mogadishu-based Elman rights group.
"Civilians fled to bush areas, some were barefoot with no belongings."
Western security agencies say Somalia -- a failed state that has been torn by civil war for nearly two decades -- has become a haven for militants including foreign jihadists, who are using it to plot attacks in the region and beyond.
The rebels want to extend their area of control from the south towards the pro-government northeastern region of Puntland. Ahmed's government controls little more than Mogadishu's sea port, the airport and his palace in the capital.
"Large forces of al Shabaab and Hizbul Islam attacked us but we chased them away after fierce fighting," said Sheikh Abdullahi Sheikh Abu Yusuf, an Ahlu Sunna Waljamaca spokesman.
"Their goal was to capture Dhusamareb, but they failed."
Residents in Marergur town spoke of fierce fighting.
"The two sides fought the whole of yesterday and they are still at face-off," Nur Abdi, an elder in Marergur, told Reuters.
"Many dead bodies are scattered all over the place and residents have fled," he said.
A local al Shabaab official, whose group has declared loyalty to al Qaeda, vowed that his forces would seize the whole region from the pro-government militia.
"We shall never stop fighting until our fighters capture the whole region and impose the Islamic sharia," Sheikh Yusuf Sheikh Isse, a senior al Shabaab official, told reporters.
At least 21,000 people have been killed in fighting in Somalia in the last three years and 1.5 million have been driven from their homes, triggering one of the world's worst humanitarian crises. (Editing by Helen Nyambura-Mwaura and Giles Elgood)