A United Nations report said Iran has hanged nearly 700 people since January, a toll that could possibly exceed 1,000 by the end of 2015.

The scathing report from a UN analyst studying the rogue nation's actions said the executions in Iran have surged over the past year with non-violent drug offenders and a number of juvenile offenders among those executed.

Two weeks ago, Iran reportedly hanged two juvenile offenders.

"[It is] an unprecedented assault on the right of life in Iran,'' said UN Special Rapporteur Ahmed Shaheed, according to Fox News. "There are dozens more waiting a similar fate on death row."

Iran's treatment of locals and foreigners, particularly foreign journalists charged with violating any of the country's law, has long been criticised by international human rights organisations.

Recently, the US government, the Washington Post and human rights groups blasted Iran for convicting Jason Rezaian, a Washington Post reporter and dual US-Iranian citizen, of charges that allegedly include espionage. He was sentenced to serve up to 20 years in prison.

Shaheed said most journalists face severe punishments "simply for reporting or airing out their views." He said some in Iran face death sentences for simply posting news articles deemed as anti-Iran on social media.

Sherif Mansour, the Middle East and North Africa programme coordinator for the Committee to Protect Journalists, said reporters often get targeted because they are "much easier to frame" as spies.

"There is a fine line that people ... in democratic societies are accustomed to. The role of the journalist is to gather information, including those related to public officials," Mansour said. "What they are trying in Iran is to blur that line."

The New York-based Committee to Protect Journalists said at least 30 journalists, including Rezaian, were held in Iranian prison at the end of 2013. Last August, state media accused a senior Wall Street Journal reporter who once served as a correspondent in Iran of conspiring against the government.

Iran has also reportedly implemented a crackdown on poets and artists in attempts to curtail freedom of expression. In December 2013, two Iranian poets were jailed for their work and sentenced to 99 lashes for shaking hands with members of the opposite sex.

One of Iran's best-known human rights activists was also arrested in May and remained in custody, according to Fox News.

In May 2014, authorities also arrested a group of young Iranian men and women for a video of them dancing to Pharrell Williams' song "Happy.'' They were sentenced to six months in jail and 91 lashes each.

In June, an Iranian court handed cartoonist Atena Farghadani a 12-year, nine-month sentence, in part for depicting Iranian parliament members as monkeys, cows and other animals, according to Amnesty International.

This month, a court sentenced award-winning Iranian filmmaker Keywan Karimi to six years in prison and up to 223 lashes for "insulting sanctities" with his movies.