- Al Shabaab rebels attacked key junction in capital
* 12 killed, 49 wounded
By Abdi Sheikh and Abdi Guled
MOGADISHU, March 3 (Reuters) - Fighting between al Shabaab rebels and African Union (AU) troops in the heart of the capital Mogadishu killed at least 12 people and wounded 49, a human rights group and witnesses said on Wednesday.
Residents said an al Shabaab truck with a mounted anti-aircraft gun approached government and AU bases near a major junction known as K4 on Tuesday, leading to deafening barrages of shells and indiscriminate exchanges of machinegun fire.
Al Qaeda-linked al Shabaab and the more moderate Hizbul Islam group have often fought together against government forces in a bid to topple the Western-backed administration which controls but a few blocks of the capital.
"At least 12 people, including children, died and 49 others were injured on Tuesday," Ali Yasin Gedi, the vice chairman of Elman group rights group told Reuters.
"The government and Islamists are engaged in a never-ending war and the people suffer more. Shells falling blindly on civilians has become the norm," he said.
Residents in the areas under government control said they initially thought the key junction linking the airport to Mogadishu's centre had been seized by the rebels.
"We thought the whole area had been captured ... government and AU forces fired from and in every direction," said resident Abdulle Ismail.
Violence has killed at least 21,000 people in the failed Horn of Africa nation since the start of 2007 and driven another 1.5 million from their homes, triggering one of the world's worst humanitarian emergencies.
Western nations and neighbouring countries say the anarchic country serves as a shelter for militants bent on launching attacks in east Africa and further afield.
In another district of Mogadishu, six al Shabaab rebels died when a mortar shell hit their house on Tuesday, sparking reprisal killings, witnesses said.
"The six dead al Shabaab were carried away in a minibus and soon two Hizbul Islam, including my cousin, were executed for spying. They were accused of directing the government's shells," said resident Fatuma Hassan.
Government and al Shabaab officials could not immediately be reached for comment. (Editing by David Clarke and Jon Hemming)