* Ivorian army launches counter-attack on Friday
* Five of dead in village raid were civilians
* Latest of raids blamed on fallen Gbagbo's backers (Recasts with army counter-attack, adds quotes, details)
By Ange Aboa
ABIDJAN, May 16 (Reuters) - Ivory Coast's army launched a counter-attack on Friday against a group of gunmen accused of entering the country from Liberia and killing at least eight people in a raid on the village of Fetai, the parliamentarian representing the region said.
Gunmen from Liberia have staged several assaults on towns near the border in recent years that the government and United Nations have blamed on allies of former president Laurent Gbagbo. Fetai was last attacked in February.
The world's top cocoa-producing nation, Ivory Coast is recovering from a decade-long political crisis that culminated in 2011 in a brief civil war after Gbagbo refused to accept his election defeat to Alassane Ouattara.
Heavily armed fighters crossed the Cavally River, which forms the boundary between Liberia and Ivory Coast, and attacked the village of Fetai early on Thursday, officials said.
"The information that I have for the moment is that five villagers were killed in Fetai," MP Yaya Coulibaly told Reuters by telephone from Grabo, a town 10 km (6 miles) from Fetai.
He said three Ivorian soldiers had also been killed.
"The FRCI (Ivorian army) have launched a counter-offensive to retake the village from the insurgents. There is fighting with heavy weapons right now," he said, adding that some 2,500 people had fled to Grabo from outlying villages for safety.
Ouattara Do, who owns a cocoa plantation near Fetai, confirmed that five civilians were killed in the initial attack on the village and said army reinforcements were pouring into Grabo as the government sought to drive out the attackers.
"The fighting (yesterday) was very heavy and we think it will be even heavier today, because the arriving FRCI are well equipped, but the Liberian rebels are also well armed."
Gbagbo is currently awaiting trial at the International Criminal Court in The Hague for suspected crimes against humanity during the 2011 war, in which around 3,000 people died.
Some 220,000 Ivorians fled into Liberia during the post-election conflict and around 46,000 - among them former pro-Gbagbo militia fighters, remain there.
A U.N. panel of experts charged with monitoring Ivory Coast's arms embargo wrote in a report last month that, despite a general improvement in security in the country, Liberia-based fighters remained a threat.
"The structure and military capacity (both in terms of combatants, weapons and related materiel) of the mercenaries in Liberia and the Ivorian militia remain highly operational."
The United Nations is gradually reducing its peacekeeping force in Ivory Coast as it faces new crises in the region, notably in Mali and Central African Republic.
Ivory Coast asked the United Nations to consider deploying drones along its border with Liberia to offset the planned peacekeeper draw-down. However their deployment has been put on hold thanks to improved security, the world body said. (Reporting by Ange Aboa; Writing by Joe Bavier; Editing by Mark Heinrich)