By Hadeel Al Shalchi
TRIPOLI (Reuters) - A week of fighting between rival tribes deep in Libya's south has killed 147 people, the government said on Saturday, but it said it had brokered a fresh ceasefire agreement between the two sides.
The clashes in the desert oasis city of Sabha were between members of the Tibu ethnic group, many of whom are originally from neighboring Chad, and local militias from Sabha.
The fighting underlines the fragility of the government's grip on Libya over six months after a revolt ended Muammar Gaddafi's rule, as well as the volatility of a country awash with weapons left over from the rebellion.
Minister of Health Fatima al-Hamroush said on Saturday that 147 people had been killed and 395 injured since the clashes broke out a week ago.
She said the government had sent 20 cars filled with medical supplies to the Sabha region and had transported 187 people from both sides of the clashes to Tripoli for medical care.
Interim prime minister Abdurrahim El-Keib told reporters a truce was now in force. The government has previously announced ceasefires over the past few days but these have collapsed.
The prime minister said a delegation including the ministers of interior, defense and health travelled to Sabha this week to broker the peace deal.
"We are pained for the south and we are sorry that the clashes reached this stage," said El-Keib. "The government is working to solve this problem. We have reached a cease fire agreement."
There are historical tensions in Libya's south between tribes who see themselves as indigenous to the country and others - such as the Tibu - who many Arab Libyans view as outsiders with roots in other parts of Africa.
In Sabha, a small-scale personal dispute ignited the underlying tensions. These quickly escalated, helped by the fact that many civilians in Libya have weapons which were looted from Gaddafi's arsenals during the rebellion.
The ruling National Transitional Council (NTC) is still struggling to assert its authority across Libya, where rival militias and tribal groups are jostling for power and resources following Gaddafi's fall.
The council is hampered by the lack of a coherent national army and has struggled to persuade the myriad militias who fought Gaddafi to put down their guns and join the national armed forces and police.
Last month dozens of people were killed in days of clashes between tribes in the far southeastern province of Al Kufra. Armed forces eventually intervened to stop the fighting in a rare example of the Tripoli government imposing its authority.
Members of the Tibu ethnic group were also involved in the fighting in Kufra.
(Editing by Christian Lowe and Ben Harding)