The United Nations Human Rights Agency (OHCHR) said more needed to be done to tackle hate speech in the tabloid press after a columnist, Katie Hopkins of British tabloid the Sun, compared migrants to "cockroaches" in an article headlined "Rescue boats? I'd use gunships to stop migrants".

The Sun newspaper, part of Rupert Murdoch's media empire, published the article by Katie Hopkins on 17 April. The day after the column was published, up to 900 people drowned when their boat capsized trying to reach Italy from Libya. Nearly 2,000 migrants have died so far this year out of nearly 40,000 trying to make the crossing.

On 25 April, UN human rights chief Zeid Ra'ad Al Hussein said the article was an extreme example of anti-foreigner articles that frequently appeared in UK tabloids, sapping compassion for people drowning in the Mediterranean in a desperate attempt to reach Europe.

Zeid said comparing people to cockroaches was reminiscent of language used by Rwandan media to incite hatred against Tutsis in the run-up to the 1994 genocide.

"This one just took it a little bit further, it used the word "cockroaches". Now this, it describes migrants as cockroaches, and this is a word that has a really terrible resonance. It was the word the Nazis used, to describe the Jews and other people they disliked, they called them cockroaches, rats, and in the Rwanda Genocide in 1994, again the Tutsis, who were slaughtered, had been described as cockroaches, by Rwandan radio and Rwandan newspapers. And in fact, the people responsible for those media organisations were ultimately convicted of genocide," OHCHR spokesman Rupert Colville said in an interview.

Britain's Metropolitan Police said it had received complaints that it amounted to incitement of racial hatred and the matter was being considered.

The independent press regulator, IPSO, said it had received more than 300 complaints about the article and was investigating whether it had breached an ethics code for editors.

"We believe more should be done to stop it, and under international law and indeed under national law, in all the European countries, hate speech is prohibited. The threshold is very high, freedom of expression is of paramount importance but there are limits and in our view this article may well have gone beyond those limits, and we are very glad that actually it has been reported to the UK police, so that was something the High Commissioner was drawing attention to, and urging the authorities to actually pay more attention to this issue," Colville said.

An online petition calling for Hopkins to resign has been signed by 280,000 people, while a separate petition calling for her to be charged has gathered 28,000 signatures.

In a new column on Friday, Hopkins thanked The Sun for "letting me speak my mind" but said the outrage her article had caused was "a cautionary tale".

Colville, who previously worked for the United Nations Refugees Agency, once wrote an article about the way migrants, asylum seekers and refugees were being talked of in British newspapers back in 2006.

He said that this rhetoric was fuelling a vicious cycle of intolerance of migrants.

"You can see violence, individual acts of violence, migrants are being attacked in streets, all across Europe, there are thousands of race-based violent crimes every single year, and this kind of rhetoric, this kind of ghastly stigmatizing of an entire group of people obviously helps foment that kind of atmosphere," Colville said.