KATHMANDU (Reuters) - Talks between the Nepali government and minority groups to resolve a dispute over a new constitution have fallen apart, opposition leaders said on Tuesday, dashing hopes that protests that have led to crippling fuel shortages will end soon.

Protesters stand near burning tyres as they gather to block the highway connecting Nepal and India, during a general strike called by Madhesi protesters demonstrating against the new constitution in Birgunj, Nepal November 5, 2015. REUTERS/Navesh Chitrakar/Files

More than 50 people have been killed since August in anti-government protests in the Tarai region, a narrow strip of plains that runs along Nepal’s southern border with India.

A resulting slowdown in cross-border truck traffic has plunged the landlocked nation into a fuel crisis that has hampered aid to survivors of last year’s deadly earthquakes and spawned a lucrative black market.

The ethnic Madhesi groups who live in the Tarai say Nepal’s new constitution, its first since the nation abolished its centuries-old monarchy, alienates their members, granting them low representation in parliament and government bodies.

After talks fell apart on Monday night, dozens of Madhesi activists burned tyres on the road in the southern business town of Birgunj, police said, in continuing protest against the charter’s carving the lowland region into federal states dominated by mountain communities.

Nepal blames India, its largest trading partner, for siding with the protesters near its border and invoking an unofficial blockade on trucks crossing from India into Nepal, a charge that India has repeatedly denied.

In the eastern border town of Kakarvitta, a long row of motorcycles and scooters stood in the middle of a bridge marking the border with India, as their owners poured smuggled fuel into their tanks.

“It’s been good business,” said a woman named Devi, who came from the Indian border town of Raniganj to sell petrol to Nepalese in plastic tubs and bottles.

The United Madhesi Front, which wants state boundaries to be redrawn to give their communities more power, said talks with government negotiators that started two weeks ago had become “meaningless”.

Defence Minister Bhim Rawal said the boundary issue would be settled by a political committee in three months, but Madhesi party leaders were not convinced.

“We can’t trust the government,” Laxman Lal Karna, another Madhesi leader, told Reuters. “We have been betrayed in the past on similar assurances.”