The number of death sentences worldwide jumped by almost 500 last year compared to 2013, mainly due to a sharp spike in sentences handed out in Egypt and Nigeria, says Amnesty International.

Amnesty’s global review of the death penalty has revealed an “alarming rise” in death sentences, including mass sentencing in both Egypt and Nigeria due to internal conflict and political instability.

At least 15 executions were carried out in Egypt in 2014 with 509 death sentences imposed, many of which were handed down as part of mass death sentences.

This notable increase in death sentences in Egypt raises concerns for Irish national Ibrahim Halawa (19) who could face the death penalty after getting caught up in violent protests in Cairo.

Colm O’Gorman, director of Amnesty International Ireland, says the Egyptian judicial system is “utterly broken” and condemns the country’s “grossly unfair process” of mass trials.

“It’s a system that’s not working and not operating by any of the accepted minimum standards required by international law,” said Mr O’Gorman. “It’s clear the mass trials in themselves are a travesty.”

“Countries are using suggestions of state security and anti-terrorism in mass trials - these are the grounds in which we’ve seen the increase in death sentences.”

Excluding China, where the numbers of executions are kept a state secret and thus impossible to determine, at least 607 executions are known to have been carried out worldwide in 2014.

Mr O’Gorman says Amnesty believes thousands are executed and sentenced to death in China every year.

“The application of the death penalty in China is shrouded in secrecy,” he said, adding that Amnesty has challenged the Chinese government to release the numbers in line with international standards.

“Beyond any doubt, China executes more than the rest of the world combined. It’s the world’s leading executioner.”

Iran, Saudi Arabia, Iraq and the USA along with China make up the world’s top five executioners for 2014.

Mr O’Gorman highlighted the “significant progress” in the drop in the number of countries carrying out executions, which has fallen from 42 countries in 1995 to 22 last year.

“It’s important we’re able to demonstrate the incredible momentum towards abolition. 140 countries are now abolitionist, that’s a huge step forward over the last thirty years.”

Despite the reduction in countries carrying out executions, the number of death sentences handed out in 2014 rose sharply. Amnesty International recorded 1,925 sentences in 2013 and 2,466 in 2014, an increase of more than a quarter.

Mr O’Gorman warns that minorities and vulnerable groups are at greater risk of facing the death penalty.

“We’ve seen many cases of women being imprisoned or executed for so called crimes that relate to their sexual victimisation,” he said, citing the case of Iranian woman Reyhaneh Jabbari who was executed last October for killing a man she said tried to rape her.

Methods of execution in 2014 included beheading, hanging, lethal injection and shooting, with public executions carried out in Iran and Saudi Arabia.

The number of executions carried out in the United States dropped from 39 in 2013 to 35 in 2014. Only seven states carried out executions with four - Texas, Missouri, Florida and Oklahoma - responsible for 89 per cent of all executions. The number of death sentences handed out fell from 95 in 2013 to 77 in 2014.

However, the state of Utah made headlines in March after it resumed the use of firing squads to carry out the death penalty when lethal injections are unavailable. It is the only state in the country to permit the practice.