By Ayman al-Warfalli

BENGHAZI (Reuters) - Ten people have been killed in the eastern Libyan city of Benghazi in fighting between army forces and Islamist groups, medics said on Saturday.

A tank battalion and armed youths fought with forces belonging to the Majlis al-Shura, a collection of armed groups including Islamist militants, in a southern district for much of Friday, army officials said.

As well as the 10 soldiers killed, some 55 were wounded, medics said on Saturday, when much of the city was quiet after gunfire had been heard in several districts the day before.

The fighting mirrors the wider struggle in the oil-producing North African state where two governments and parliaments, allied to rival armed groups, are vying for control almost four years after the ousting of Muammar Gaddafi.

The unrecognised government, which controls the capital Tripoli, in western Libya, has pledged to the back the Islamists in the east after the forces of the internationally recognised government launched an offensive against them in October.

The army, which is loyal to the official government, expelled the Islamists from the airport area and from several camps the army had lost during the summer.

But fighting has been raging on in several other parts.

The recognised prime minister, Abdullah al-Thinni, was forced to leave Tripoli in August for the eastern city of Bayda when a group called Libya Dawn seized the capital.

The Tripoli government, which is backed by some Islamist groups, said it would support Majlis al-Shura.

Part of Majlis al-Shura is the Islamist militant group of Ansar al-Sharia, blamed by Washington for an assault on the U.S. consulate in Benghazi 2012, which killed the U.S. ambassador.

"The national salvation government confirms ... giving full support, without limits, to Majlis al-Shura troops," it said in a statement posted on the cabinet website. It gave no details.

The Tripoli rulers have not been recognised by the United Nations or world powers. Both sides have fought each other on several fronts, undermining six months of U.N. meditation efforts which have produced little progress.