* Tripoli forces fighting Haftar troops for Libyan capital
* Yarmouk barracks has switched hands between the two sides
* Yarmouk shows Haftar's one month offensive has beeninconclusive
* Residents, analysts expect long battle
By Ulf Laessing
TRIPOLI, May 10 (Reuters) - Fighters allied to Libya'sU.N.-backed government posted selfies from a barracks one daylast month to mark their progress in a battle for Tripoli.
Later that day, opposition troops belonging to easterncommander Khalifa Haftar did the same from the identical spot toshow they had taken it back.
Yarmouk camp, a barracks in southern Tripoli, has switchedhands between the two sides at least five times since thebeginning of April, according to online videos.
Government forces have held Yarmouk for at least a week now,but the situation is fluid.
Its shifting fate underscores how Haftar's one monthoffensive on the capital city has been inconclusive and suggeststhat fighting could last for many months more.
Regions, tribes and armed groups have been vying for controlof Libya, a major oil and gas producer, since the uprising thattoppled Muammar Gaddafi in 2011.
The latest battle for Tripoli is the largest mobilisation ofopposing forces since then, and Haftar's Libyan National Army(LNA) and government troops exchange fire daily.
But the frontline has barely moved. Haftar's tanks andvehicles are stuck in Tripoli's southern suburbs. Fighters takevideos to document progress before losing ground again andanalysts and residents expect a protracted battle.
"This war could drag on for a long time. Both sides remainconfident, have men in reserves and friends capable of re-armingthem," said Tarek Megerisi, policy fellow at the EuropeanCouncil on Foreign Relations.
OUTSIDE SUPPORT
While the Tripoli forces have the backing of the UnitedNations, Haftar has the support of the United Arab Emirates andEgypt, which have helped trained his soldiers. Some Westerncountries are also sympathetic to Haftar. He received militarysupport from France which helped him take over the eastern cityof Benghazi in 2017.
More than 60,000 people have been displaced from Tripolisince the offensive started on April 4. The World HealthOrganisation said 443 people have died and 2,110 have beeninjured.
Diplomats note that the LNA has not yet engaged in all-outurban warfare as it did in Benghazi from 2014 to 2017, whenartillery guns and jets hammered Islamists holed up inbuildings, flattening entire districts. The LNA blamed theIslamists for indiscriminate shelling.
The battle for Benghazi and later Derna, another easterncity taken by Haftar, took place largely out of sight of theinternational community. Few diplomats and foreign reporterstravelled east because it was dangerous and visas were scarce.
Such a heavy-handed strategy would be more difficult inTripoli, where the government has issued visas for dozens ofreporters. The U.N. has a large mission still on the ground andsome Western embassies have stayed open.
The Tripoli forces have pushed back the LNA in some areas,but Haftar is sending more troops and some residents fear moreaggressive tactics are on the way.
"We can hear shelling every day but only God knows what willhappen," said Mohammed Trabulsi, who has a bag shop near thefrontline in the Salahudin district. He has very few customersthese days.
"I expect the situation to get worse."
The Tripoli government has accused the LNA of indiscriminateshelling. The LNA denies shelling residential areas.
Haftar, a former Gaddafi general, hoped locals in Tripoliwould help him advance. Some initially supported him, but manyof them have changed their minds during the fighting.
"I was with Haftar but not any longer," said 26-year-oldTripoli resident Mohammed Duri. "I don't like the armed groupswe have here but you can't shell a city and then rule it."
Instead, Haftar is bolstering his offensive with extratroops and fire power. A convoy including armed vehicles forurban warfare was spotted last week south of Tripoli, adiplomatic source said.
LNA sources say he has other troops left in the east. Hiselite Saiqa (Lightning) force around 3,500 members but only afew hundred are on the frontline.
NO WINNER
Yarmouk's wide streets are easy for tanks to navigate butits low buildings make it hard to set up a position of command.
Higher residential buildings rise up beyond the lastcheckpoint of the frontline. They are still occupied and shopsare open, although they have few customers.
The Tripoli forces could position their snipers there toslow any attempt by the LNA to advance to the north, as othershave done in previous battles in the capital.
While they may be able to defend the north, it would bedifficult to push the LNA back towards the east, said analystMegerisi.
Those defending Tripoli from the LNA say they have plenty ofammunition with fresh supplies from several western towns.
But with little coordination amongst the different groups,some commanders are reluctant to pass on shipments for fear thatit will be sold or stored by those whose loyalty might change,sources say.
Some of the armed groups now defending Tripoli fought eachother for weeks in September over access to state funds. Theyhave patched over their differences to unite against Haftar, butLNA supporters hope some will change sides if he advances.
Megerisi fears the different groups are becoming embroiledin a war with no winner.
"Win is a big term here, it suggests some element offinality," he said.
"The real fear for Libya is that the war does drag, andescalate, because the more outside powers invest and the moreLibyans die for their cause, the more intractable this war willbecome."(Editing by Anna Willard)
