UPDATE 1-Libya rebels say Gaddafi forces retreat in east
* Insurgents encircle strategic oil town, spokesman says
* Mines take heavy toll on rebel force
(Adds detail on landmines, refinery, background on fighting)
CAIRO, July 18 (Reuters) - Libyan rebels have routed most of Muammar Gaddafi's militias from the oil town of Brega but will have to clear landmines littering the streets before they can take full control of the area, a rebel spokesman said on Monday.
Rebel fighters have encircled Brega, a key oil export terminal with a refinery and chemical plant which for months marked the eastern limit of Gaddafi's control, but are staying out of the centre, rebel spokeman Shamsiddin Abdulmolah said.
"The main body (of Gaddafi's forces) retreated to Ras Lanuf," Abdulmolah said by telephone. "I am told they have some four-wheel-drive trucks with machineguns spread out between Ras Lanuf and Bishr."
Ras Lanuf, another major oil export centre, lies some 100 km (62 miles) west of Brega.
He said rebels trying to take control of Brega had been hindered by landmines laid by Gaddafi loyalists across the town, on its desert outskirts and at its oil installations.
"The main (oil) installations are still mined and the remnants of Gaddafi's forces are still there," said Abdulmolah. "Cleaning them out is going to be a bit difficult without damaging the facilities themselves." Continued...