A newspaper in the Mexican border city of Ciudad Juarez has closed down because a spate of unsolved murders of journalists have made it too dangerous to go on.

El Norte executive, Oscar Cantu Murguia, informed readers of the decision in a farewell letter titled 'Adios!' which was published on the paper's front page and also online.

He cited the recent murder of journalist Miroslava Breach in the nearby city of Chihuahua.

The front page of El Norte carries the headline 'Goodbye!' as it announces it is closing

Breach was a reporter for the national newspaper La Jornada but had worked closely with El Norte on a number of stories.

Cantu wrote: 'On this day, esteemed reader, I address you to report that I have made the decision to close this newspaper due to the fact that, among other things, there are neither the guarantees nor the security to exercise critical, counterbalance journalism.'

El Norte translates as The North and covers the northern Mexican city of Juarez, a border town which has been plagued by violence and drug wars for 40 years.

It is home to the notorious Juarez Cartel, which was founded by Amado Carrillo Fuentes, the 'Lord of the Skies', in 1970.

He died during a plastic surgery operation in 1997 and the Cartel is currently run by his brother Vicente, who was arrested in 2014.

A woman lights a candle next to photos of Mexican journalist Miroslava Breach, who was gunned down in the northern state of Chihuahua on March 23

At least 38 journalists have been killed in Mexico since 1992 for motives confirmed as related to their work, according to the Committee to Protect Journalists (CPJ).

Another 50 were slain in the same period for reasons which remain unclear.

Breach was gunned down as she left home on March 23. Two other journalists were killed in Guerrero and Veracruz states.

Another journalist was shot in Poza Rica, Veracruz, on March 29, leaving him in a critical condition, and an attack on a journalist in San Jose del Cabo, Baja California Sur, left his bodyguard dead.

A message in red ink reads 'No More Deaths' next to a photograph of Miroslava Breach. The number of journalists killed in Mexico since 1992 has risen to 88

Carlos Lauria, from the CPJ, said: 'Mexico is clearly going through a deep, full-blown freedom of expression crisis.

'It's affecting Mexicans, not only journalists, because the fact that a newspaper closes is depriving people of information that they need in order to take informed decisions.'

In his letter to readers of El Norte, Cantu wrote: 'Everything in life has a beginning and an end, a price to pay. And if this is life, I am not prepared for any more of my collaborators to pay it, nor with my own person.'

Cantu also hinted at financial problems, saying the authorities were guilty of 'the arrogant refusal to pay debts contracted for the provision of services'.

Government advertising is a major source of revenue for many Mexican news outlets and critics say it sometimes leads to self-censorship.