WASHINGTON (NYTIMES) - An online appeal for donations to organise flights to rescue vulnerable Afghans from the Taleban has quickly found a large audience of Americans eager to help.

In one day, more than 100,000 people donated more than US$5.8 million (S$7.9 million) to the effort in Afghanistan, exceeding its initial goal of raising US$4.4 million.

The question, according to some outside specialists, is whether the group behind the effort has the experience and organisational capability - let alone permission from the US government - to rescue and resettle hundreds of desperate Afghans.

The GoFundMe campaign was organised by Mr Tommy Marcus, who runs Quentin Quarantino, an Instagram account known for promoting left-wing memes and political causes, with nearly 770,000 followers.

Others involved include military veterans, a former Republican operative and the International Women's Media Foundation.

Mr Marcus says in his appeal that he has been working with humanitarian aid groups, veterans and activists on the ground in Kabul, "fighting to save people who otherwise have no chance at survival in the Taleban-occupied Kabul".

The mission, he said, is focused on men and women who have worked as human-rights lawyers, champions of women's and LGBTQ (lesbian, gay, bisexual, transgender and queer) rights, journalists, government liaisons, artists and interpreters, "all of whom are at imminent risk of being executed by the Taleban, along with their families".

The money, according to the campaign, will be paid to and distributed by Raven Advisory, a company based in Fayetteville, North Carolina, which says on it website that it has experience working in Afghanistan and provides training, risk management, security, consulting and other services.

Company chief executive Sheffield Ford and chief operating officer David Heldt served in the US Special Forces, while senior executive vice-president Philip Raveling was in the Central Intelligence Agency, according to the company website.

The company had no immediate response to questions about the campaign. A Raven executive referred them to a spokesman, who said he was still working on a statement.

All the Afghans who board the flights will have identification and access to the airport and be vetted and sponsored, according to the organisers.

"Everyone volunteering on this project is doing so for free," the organisers wrote. "Every dollar goes back to these Afghan refugees. We are not taking a penny."

The mission, however, has prompted concern from some refugee specialists.

Tufts University's professor of global migration Karen Jacobsen said the effort "sounds crazy".

"There are several large problems that immediately occur to me, but the most obvious one is that all these rescued people will immediately bump up against the US immigration system," she said, adding that they may not be allowed to even enter the country.

Mr Eskinder Negash, president and CEO of the US Committee for Refugees and Immigrants, said the mission would have to be planned with the State, Defence and Homeland Security departments to ensure that the Afghans have clearance and medical screenings to enter America.

"It has to be organised and structured, and it has to be coordinated. Otherwise, it's going to be a problem for the people who come in," Mr Negash said. "They may not be eligible to become special immigrant visa holders."

He added: "It's well-intentioned. It's wonderful. But as you know, sometimes the road to hell is paved with good intentions."

In a statement, the US State Department said: "We appreciate community-led efforts to support the Afghan relocation and resettlement process, which reflects the generosity of the American people and the international community.

"However, we are unable to verify the authenticity or effectiveness of these efforts."

Mr Marcus said he planned to speak more about the effort soon.

Mr Phil Caruso, a board member at No One Left Behind, a non-profit that supports Afghan war allies, said the GoFundMe group is one of many that have contacted his organisation for assistance regarding trying to organise rescue flights.

The group, he said, wanted to know if No One Left Behind had flights that it could fund.

All the rescue missions, he said, are facing a thicket of logistical and legal challenges. The most immediate, he said, is ensuring that Afghans can clear Taleban and US checkpoints along the way to Kabul's international airport and get through the crowds of people outside.

Those boarding the flights must also have visas or be eligible for visas, and the private flights need permission from the US State and Defence departments to land at one of several designated military bases, he said.

"We're still trying to work through these logistics now, but there's not a clear answer yet," he said.

Mr Caruso, a veteran who served twice in Afghanistan, said the US has a "moral obligation" to help Afghans fleeing the Taleban.

"Like most veterans, I spent a lot of time working with Afghans, and I feel a kinship with the people," he said. "Putting politics aside, we just want to help as many people as we can."

GoFundMe said the company had fully vetted the appeal, as it does with all fund-raisers related to Afghanistan, to ensure that it complies with the law and global financial regulations. The company said it had been in contact with the organisers of all these fund-raisers, including Mr Marcus, "to ensure the aid is sent safely and securely to those in need".

Ms Becca Heller, executive director of the International Refugee Assistance Project, said the GoFundMe is one of many similar efforts that philanthropists and private foundations are trying to organise to rescue people from Afghanistan.

"I see something like this, and I'm like, 'Great. I hope it works'," Ms Heller said. "We're talking every day to people on the ground who are so desperate to get out, and the pace of the US government is not fast enough."

Ms Heller said the strong response to the GoFundMe effort should also send a message to the Biden administration about the depth of public support for refugee programmes.

"The outpouring of support from everyday Americans is a signal that there are activated people invested in things like this happening, and they're paying attention," she said.

According to the organisers, any money raised that is not spent on rescue flights will be donated to the International Women's Media Foundation.

Ms Charlotte Fox, a spokesman for the foundation, said the group was working on the mission with other organisations, including the Journalists in Distress Network, which has experience extracting people and resettling them under difficult circumstances.

"We are working to get out as many people as we can, and it truly isn't a single effort," Ms Fox said. "These people will need continual help."