Dozens of sailors aboard an Iranian oil tanker that blew up and sank off the coast of China yesterday had 'no hope' of being saved, a maritime official has said.

The collision and disaster of the Sanchi, which carried 30 Iranians and two Bangladeshis, had transfixed an Iran still reeling from days of protests and unrest that swept the country at the start of the year.

Families of the sailors wept and screamed at the headquarters of the National Iranian Tanker Co in Tehran, the private firm that owns the Sanchi.

Some needed to be taken by ambulance to nearby hospitals as they were so overwhelmed by the news.

'No hope of finding survivors': Two bodies were recovered from the tanker yesterday, and another body was found on Monday and taken to Shanghai for identification

The crash happened last Saturday when an oil tanker collided with a freighter in the East China Sea, 114 miles off China's coast

'Thirty-two people died without a funeral and without coffins! They burned to ashes while their families were wailing here!' cried out one woman who didn't give her name.

The government 'has come after 10 days to sympathize with them? What sympathy are you talking about?'

State TV earlier quoted Mahmoud Rastad, the chief of Iran's maritime agency, as saying: 'There is no hope of finding survivors among the [missing] 29 members of the crew.'

President Hassan Rouhani expressed his condolences and called on relevant government agencies to investigate the tragedy and take any necessary legal measures, according to state TV.

In a message, Iran's Supreme Leader Ayatollah Ali Khamenei expressed his condolences and sympathy with the victims' families, his own website, Khamenei.ir, reported Sunday. The government also announced Monday as a nationwide day of public mourning over the disaster.

The cause of the Janunary 6 collision between the Sanchi and the Chinese freighter CF Crystal, 160 miles off the coast of Shanghai, remains unclear. The CF Crystal had 21 crew members, all of whom were reported safe.

Chinese state media also said the ship's voice data recorder, which functions like 'black boxes' on aircraft, had been recovered. Pictured: A rescue ship works to extinguish the fire on the burning Iranian oil tanker Sanchi

But the Sanchi, carrying nearly 1 million barrels of a gassy, ultra-light oil bound for South Korea, burst into flames.

Chinese officials blamed poor weather for complicating their rescue efforts. Thirteen ships, including one from South Korea and two from Japan, engaged in the rescue and cleanup effort Saturday, spraying foam in an effort to extinguish the fire.

The Chinese freighter's 21 crew members were all accounted for. The burning oil tanker's crew consisted of 32 members

But around noon on Sunday, Chinese state media reported that a large explosion shook the Sanchi, its hull and superstructure completely stripped of paint by the flames. The ship then sank into the sea.

The Chinese say the ship left a 3.8-square-mile area contaminated with oil. However, the condensate oil the ship was carrying readily evaporates or burns off in a fire, reducing the chance of a major oil spill.

Chinese state media also said the ship's voice data recorder, which functions like 'black boxes' on aircraft, had been recovered. Three bodies have been recovered from the sea, leaving 29 crew members still unaccounted for.

The tanker has operated under five different names since it was built in 2008, according to the UN-run International Maritime Organization. The National Iranian Tanker Co describes itself as operating the largest tanker fleet in the Middle East.

It's the second collision for a ship from the National Iranian Tanker Co in less than a year and a half.

In August 2016, one of its tankers collided with a Swiss container ship in the Singapore Strait, damaging both ships but causing no injuries or oil spill.