El Salvador’s Congress has approved a request by President Nayib Bukele to criminalise gang-related messages in the media, including news outlets, in a step to control the rising cases of homicides in the Latin American nation.

The move on Tuesday, which includes 10 to 15-year sentences for offenders, comes amid a government crackdown on gangs that has led to one of the world’s highest murder rates. The crackdown, which included Bukele invoking emergency powers to suspend some constitutional rights in February, has led to concerns over human rights abuses.

“When the Germans wanted to eradicate Nazism, they prohibited by law all Nazi symbology, as well as messages, apologies and everything aimed at promoting Nazism,” Bukele wrote on Twitter. “Now we will do the same with gangs.”

The reform to the penal code applies to those who “reproduce and transmit messages or communications originating or allegedly originating from said criminal groups that could generate anxiety and panic among the general population”.

The measure also targets those who “mark” their territories with acronyms, referring to a common practice gang members use to threaten those who report them to authorities.

The new policy was quickly met with “concern” from El Salvador’s journalists’ association over what they called a “clear attempt at censorship”.

In a statement, the group refered to the measure as a “gag” reform, saying it “threatens with imprisonment the media and journalists who report on a reality that the current administration … seeks to hide.”

They called the measure a “new tool to criminalise journalistic work”.

El Salvador declared a state of emergency on March 27 following three days of intense violence in which the government registered 87 murders, 62 of those occurring in just a single day.

In the days since, Salvadoran authorities have arrested 6,312 alleged gang members.

Last week, Congress increased the maximum prison sentence for being a gang member from nine to 45 years. The government also raised maximum prison sentences for children and will allow teenagers to be tried as adults for the most serious offences, and serve their sentences in adult prisons rather than juvenile detention facilities.

On Tuesday, the office of the United Nations High Commissioner for Human Rights expressed concern about the government’s approach, citing “alleged cruel, inhuman or degrading treatment”.

“In addition to the state of emergency, we are deeply concerned about certain amendments to criminal law and criminal procedure,” said the office’s spokeswoman Liz Throssell.