When Tohid Najafi first learned that a devastating 7.3 magnitude earthquake had struck his native country, Iran, he wasted no time.

A medical professional based in Detroit, US, Najafi quickly set up a Facebook page to raise money for the families of the victims and the survivors of Sunday's disaster.

The quake killed at least 450 people and injured more than 7,000 in Iran and neighbouring Iraq. An estimated 15,000 houses were destroyed, leaving some 70,000 people homeless and faced with a bleak future.

Seeing the extent of the damage, Najafi on Monday rallied the 65,000 members of his online group, Persian Americans, to help.

He set a goal for $110,000 over the next month and hoped that within the first day he would manage to raise up to $15,000.

But when he woke up the next morning, online donors had already chipped in more than $80,000. By Wednesday, the sum raised had surpassed $200,000.

"I was very surprised," Najafi told Al Jazeera, saying he had doubts about hitting his goal on time - raising money online is a "novel thing" among the Iranian-American community, he said.

But his delight was short-lived.

On the first day of his effort, Najafi received a message by Facebook informing him the funds "will not be released", until the social media site receives from him the required authorisation from the United States Department of Treasury.

Najafi then had to figure out how to get the money released from Facebook without getting in trouble with the US authorities.

He also had to fend off sceptics, who questioned if he could be entrusted with the sum. The fund, however, is controlled by Facebook, not Najafi.

On Thursday, to Najafi's dismay, Facebook took down his fundraising page, saying "personal fundraisers are not eligible to receive funds for nonprofits".

Just as Najafi launched his initiative, Tara Kangarlou, a New York-based Iranian-American journalist, also started a personal fundraising effort to help the victims of the devastation.

Within the first 30 minutes, she had raised $2,000 on the YouCaring fundraising site.

Kangarlou, who had previously raised money for Syrian refugees, was hoping the money would help buy much-needed medicine, food and blankets for the victims.

Despite the US Treasury's exemptions on its policy on disaster relief to Iranian individuals, YouCaring cancelled Kangarlou's page.

In a message, which she re-posted on social media, the site said her fundraiser had been removed "because the country you provided is part of an embargoed region".

"The United States Treasury Department does not allow our platform to disburse funds directly to, or be routed by proxy to a state or person that is currently located in an embargoed region," the letter read.

She was also told that the third-party money transfer partner, WePay, is not authorised to do business with Iran.

"As soon as they saw the name Iran, that this is for Iran earthquake, they freaked out," Kangarlou told Al Jazeera.

"YouCaring did not care, nor did WePay," she said. "What a shame."

Al Jazeera contacted YouCaring and WePay online and by phone but did not receive a response.

Layers of restrictions

For decades, the US has imposed wide-ranging military and economic sanctions against Iran, following years of hostilities starting with the 1979 Iranian Revolution and the storming of the US embassy in Iran's capital, Tehran.

Following the 2015 nuclear deal between Iran and world powers, including the US, some restrictions have been lifted, including the trading of Iranian oil and gas in the world market.

But the US maintains a comprehensive trade embargo with Iran, which includes prohibitions on direct banking between the two nations.

The Office of Foreign Assets Control (OFAC), under the US Department of Treasury, has issued exemptions allowing US citizens and residents to lawfully engage in certain activities to help out relief efforts, such as following an earthquake.

For instance, individuals in the US are allowed to make donations to US non-governmental organisations with OFAC authorisation to operate in Iran.

Transfers of personal remittances "to assist a family member or a friend" is also allowed provided that the payment is processed through a third-country financial institution. However, experts say foreign banks are often reluctant to process such donations out of fear of potential fines and other complications.

US-based donors are not permitted to send funds directly, even to charitable and humanitarian groups already on the ground in Iran, such as the Iranian Red Crescent, a group with a wide network and presence in many areas.

They are also prohibited from sending goods or technologies, including those intended for humanitarian relief.

The Washington, DC-based National Iranian American Council (NIAC) has been lobbying for years to lift those US sanctions on humanitarian grounds.

However, that is becoming more unlikely now under President Donald Trump's administration, according to Trita Parsi, founder and president of NIAC.

"President Trump has not shown any human side that would extend itself to a country and the people like Iran," he told Al Jazeera.

"If sanctions are really hindering emergency aid after an earthquake, I think that really shows the problematic aspect of the sanctions," added Parsi.

'Slow, complex, impossible'

On Tuesday, the Iranian Red Crescent said it had reached 90 percent of the areas affected by the quake. But donating to it from the US is not possible as the organisation is not among those with an OFAC authorisation.

However, there are smaller humanitarian organisations allowed by the US to carry out relief efforts in Iran, and Parsi encouraged people to contribute to groups such as Moms Against Poverty (MAP), Child Foundation, Children of Persia and Relief International.

"The problem is, some of the organisations that are actually on the front line, you cannot support as a result of the US sanctions," he said, citing the Iranian Red Crescent.

"That's part of the reason why a lot of people in the Iranian American community and beyond are very unhappy with the sanctions."

The obstacles to relief fundraising, however, are not limited to efforts inside the US.

Initiatives conducted outside the country also face hurdles, as a number of foreign banks with connections to US financial institutions have also refused to handle payments to Iran.

Ellie Geranmayeh, an Iran expert at the European Council on Foreign Relations, said that "it is virtually impossible" to donate directly from Britain to humanitarian relief organisations already in Iran helping with earthquake victims.

Geranmayeh cited "over compliance" of the UK banks has prompted them to "refuse to transact to accounts with 'Iran' in the title".

"The process is everything it's not meant to be when responding to a disaster: Slow, complex and at times impossible," she told Al Jazeera.

Before Facebook took down his fundraising page, Najafi had already been considering his options for sending the money he had raised to Iran. He had wanted to direct part of the money to MAP, a group authorised by the US Treasury to operate in the country.

The medical professional told Al Jazeera that he would have also wanted to direct another part of the fund through different organisations such as Child Foundation, another US-authorised group.

Earlier, Najafi expressed disappointment with what he described as Facebook's slow process to release the funds to the organisations he chose.

Then came the surprise early on Thursday, when Facebook cancelled his fundraising page.

"We are working on the best way to handle this and have paused your fundraiser for now," the message said, promising to discuss with Najafi how to move forward.

Al Jazeera contacted Facebook's communications team, but only received an automated reply saying, "We'll do our best to get back to you as soon as possible". Facebook did not provide a phone number to contact their communications office.

As for Kangarlou, the journalist decided to refund those who had donated in her cancelled YouCaring page.

"However, I will match the contributions in a personal capacity, and make sure it gets into the hands of those in need," she wrote on her Facebook Page.

She said the US government "should not make it difficult" when people want to help those in need in Iran when a disaster strikes.

"The way it is now, it is extremely difficult. These are the moments that you realise how political tug of war are hurting ordinary Iranians."