BANGKOK (Reuters) - Thailand’s army has reached a breakthrough pact with a Muslim separatist group to create a safety zone in restive southern provinces, the lead negotiator said on Wednesday, but analysts queried if it could succeed without support from other groups.

A decades-old insurgency in the Muslim-majority southern provinces of Yala, Pattani and Narathiwat has claimed more than 6,500 lives since it escalated in 2004, says independent monitoring group Deep South Watch.

The government has been negotiating with Mara Pattani, a longstanding umbrella group that claims to speak for the insurgents.

“Both sides have agreed to the creation of a safety zone in one of the three southern provinces to show their good faith,” negotiator Major General Sithi Trakulwong told Reuters.

“This is the most progress we’ve made in over two years of negotiations.”

Mara Pattani officials were not immediately available for comment.

Sithi said the agreement would be finalized next week in neighbouring Malaysia, which has facilitated the discussions, once senior army officials arrive to conclude the talks.

The safety zones would be an area where fighting is off-limits, but precise details of its location or size have not been made clear.

Talks between the government and the insurgents began in 2013 under then Prime Minister Yingluck Shinawatra, but stalled after the military overthrew her government in 2014.

Analysts say the government is negotiating with a group comprised mostly of exiled fighters that does not carry weight on the ground.

The insurgent group Barisan Revolusi Nasional (BRN), which has been left out of negotiations, is now the main actor in the three provinces, they say.

“Any agreement on the implementation of safety zones that does not include the military wing of BRN will very likely result in an escalation of violence,” Anthony Davis, a Bangkok-based security analyst with IHS-Jane’s, told Reuters.

A string of bombings killed four Thais and wounded dozens of people, including foreigners, in tourist towns in August, raising fears that insurgent violence was spilling out of the far south.

Mara Pattani said in negotiations with the Thai government that it was not responsible for the attacks. BRN made no comment on the attacks.