Survivors of slave auctions in Libya have described a "total hell" that they wouldn't wish on their "worst enemy" after a recent revelation of a slave trade shocked the international community.

"We were slaves," said Moussa Sanogo, a migrant who flew back to Ivory Coast from Libya this week after surviving regular beatings and forced labor in the fields.

"For the Arabs [Libyan jailers], black-skinned men are nothing but animals -- animals were treated better," said Sanogo, who spent more than four months in Libya trying to get to Italy by boat, as reported by AFP.

He was just one of those who returned home with stories similar to those aired last week by U.S. TV network CNN, which showed an apparent slave auction where black men were presented to North African buyers as potential farmhands and sold off for as little as $400 (340 euros). The video, which the Thomson Reuters Foundation could not independently verify, was the first footage of people being sold, said Mary Fitzgerald, an independent researcher on Libya, according to Reuters.

"It was total hell in Libya," said Maxime Ndong, one of 250 migrants flown back to Cameroon on Tuesday night. "There is a trade in black people there. People who want slaves... come to buy them," he told AFP. "If you resist, they shoot at you. There have been deaths," said Ndong, who spent eight months in Libya.

Young African men bound for Europe are frequently caught in trafficking networks and sold for labor in Libya, where many migrants are detained, tortured, and even killed, according to the U.N. International Organization for Migration (IOM). At least 20,000 migrants are being detained in Libya, which is the main gateway for Africans to reach Europe, according to the IOM.

The president of the U.N. General Assembly said on Twitter he was "appalled" by the reports of slave auctions, and the African Union called for an immediate end to the practice.

Protesters gathered outside the Libyan embassies in Paris and in African capitals including Bamako, Mali and Conakry, Guinea over the weekend and on Monday, according to local news reports. A protest is planned in London later this week. Many Libyans used the hashtag #LibyansAgainstSlavery on Facebook and Twitter, expressing horror and disapproval.

"People are rightfully outraged, but don't hold your breath that anything real is going to happen," Human Rights Watch (HRW) researcher Hanan Salah told the Thomson Reuters Foundation.

Libya, the oil-rich North African country, descended into chaos after Western intervention, and parts of it have become a bastion for Daesh, giving the militants a new base even as its territory in Syria and Iraq shrinks under constant assault. Five years after Libyan leader Moammar Gadhafi was toppled by NATO intervention, the country has become the main jump-off point for migrants heading for Europe, and the breeding ground for militants as there is no security or stability left in the war-torn country.