LES CAYES: An earthquake that killed about 2,000 people in Haiti had left the Caribbean nation "on its knees", Prime Minister Ariel Henry said on Wednesday, as survivors showed increasing frustration about the sluggish arrival of relief to hard-hit areas.

Henry had on Sunday flown to Les Cayes, the southwestern city of 100,000 people which bore the brunt of Saturday's magnitude 7.2 quake, and pledged a rapid increase in aid. But in a video address on Wednesday evening, he conceded Haiti was in trouble.

"Haiti is now on its knees," Henry said. "The earthquake that devastated a large part of the south of the country proves once again our limits, and how fragile we are."

Dozens of people went to Les Cayes airport demanding food after a helicopter arrived carrying supplies, a Reuters witness said. Police intervened to allow a truck carrying aid to leave.

Following another night of rains, residents in Les Cayes, including those camped in a mushrooming tent city in the city center, complained of scant assistance.

Concern was also growing for more remote places outside Les Cayes such as Jeremie to the northwest, where access roads were damaged, videos on social media showed.

Pierre Cenel, a judge in Les Cayes, rebuked the government in Port-au-Prince.

"As a judge, I must not have a political opinion. But as a man, as a man concerned about the situation of my country, nothing is working. They didn't do anything to prepare for this disaster," Cenel said.

The poorest country in the Americas, Haiti is still recovering from a 2010 quake that killed over 200,000. The latest calamity hit just weeks after President Jovenel Moise was assassinated on July 7, plunging Haiti into political turmoil.

Jerry Chandler, head of Haiti's civil protection agency, told a news conference he knew aid had yet to reach many areas but officials were working hard to deliver it.

"The frustration and despair of the population is understood, but ... the population is asked not to block the convoys so that civil protection can do its job," he said.

There were at least 600,000 people in need of humanitarian assistance and 135,000 families displaced, Chandler said. The goal was to deliver aid to everyone in need within a week.

RISK OF DISEASE

In the tent city in Les Cayes displaced residents were getting worried.

"We need help," said Roosevelt Milford, a pastor speaking on radio on behalf of the hundreds camping out in soggy fields since the quake destroyed their homes.

Milford and others complained they lacked even the most basic provisions, such as food, clean drinking water, and shelter from the rain. Tanks of drinking water were destroyed during the quake, authorities said.

Tropical Storm Grace this week swept away many shelters and inundated the field.

Moril Jeudy, a community leader in Marigot south of Port-au-Prince, said while the town had emerged intact from the quake, Grace had flooded hundreds of homes, killed four people and left several more missing. And no help had arrived yet.

"Even the NGOs didn't come," he said.

Security concerns about gang-controlled areas on the route from the capital Port-au-Prince, slowed aid access.

The U.N. Office for the Coordination of Humanitarian Affairs said negotiations with armed groups had permitted a humanitarian convoy to reach Les Cayes.

Chandler said the government was increasing the number of aid convoys going by land, and aimed to reach three a day soon.

In L'Asile, a town of over 30,000 people 60 km (40 miles) northeast of Les Cayes, community leader Aldorf Hilaire said government help had yet to arrive, and survivors were relying on support from charities such as Doctors Without Borders.

"We are desperate," he told Reuters. "The springs are dirty: the water is not drinkable ... We had a bad night during the storm and the people need tents and tarps."

Authorities have said the earthquake killed at least 1,941 people and injured some 9,900 others, but with rescuers still pulling bodies from the rubble the tally looks set to rise.

In a rare piece of good news, 34 people had been rescued in the last two days, Chandler said. But hopes are fading.