Ahead of international religious freedom day tomorrow, a cross-party group of MPs has released a report showing that almost 85 per cent of the world's population are linked to a faith and more than 80 per cent live in countries with 'high' or 'very high' levels of hostilities towards certain beliefs. Persecution appears to be increasing globally.

Here are five of the worst offenders against religious freedom in the world.

North Korea

North Korea's constitution may guarantee religious freedom, but the oppressive state is officially atheist. Because of extreme governmental control over information, it is difficult to establish just how bad repression of those with religious faith is in North Korea. Citizens caught with a Bible face imprisonment, torture or even death. According to a report earlier this month from the leading Catholic charity Aid to the Church in Need, believers face 'enforced starvation, abortion, and reports of faithful being hung on crosses over a fire and others being crushed under a steamroller'. CSW, a UK-based religious freedom charity, said in a report released last September that freedom of religion or belief 'is largely non-existent' under dictator Kim Jong-Un's leadership.

'Religious beliefs are seen as a threat to the loyalty demanded by the Supreme Leader, so anyone holding these beliefs is severely persecuted,' the report said. 'Christians suffer significantly because of the anti-revolutionary and imperialist labels attached to them by the country's leadership.' Among the documented incidents against Christians are 'being hung on a cross over a fire, crushed under a steamroller, herded off bridges and trampled underfoot'.

China

The ruling Chinese Communist Party is officially atheist. Five religious groups — Buddhists, Taoists, Muslims, Catholics and Protestants — can register with the government and legally hold services. But adherents of unregistered faiths including Uighur Muslims and Tibetan Buddhists and evangelical Christians unwilling to come under State supervision have faced forced conversion, torture and imprisonment.

The charity China Aid, in its 2016 Annual Persecution Report, said Christians are being persecuted 'at a frequency unseen since the Cultural Revolution'. Persecution cases went up by more than 20 per cent last year compared to 2015, the number of people detained increased by nearly 150 per cent, arrests went up 11 per cent, those sentenced increased by a third, abuse cases went up more than 40 per cent and the actual number of people abused increased by nearly 70 per cent.

Iran

Iran's constitution offers some religious freedom rights for recognised sects of Islam along with Christians and Jews. But evangelical Christians and other faith groups face persecution for violating bans on proselytizing. People from religious minorities have in recent years been imprisoned in harsh conditions for committing 'enmity against God' and spreading 'anti-Islamic propaganda'. In August, Christian Today reported on how some 500 Christian converts from Iran have sought asylum in Turkey following persecution by the authorities.

Nigeria

In Nigeria, International Christian Concern (ICC) has said that Christians face 'brutal daily persecution for their faith from the Islamic extremist groups Boko Haram and the Fulani militias'. The government's attempt to eradicate Boko Haram - whose leadership has vowed to eradicate Christianity in Nigeria - has been 'a massive failure overall', ICC said, and 'has only refocused them [Boko Haram] on attacking Christians'. In May, eighty-two Chibok schoolgirls seized three years ago by Boko Haram were freed in exchange for detained suspects after the prolongued battle to save nearly 300 girls whose mass abduction exposed the mounting threat posed by the fighters, who are linked to Islamic State.

Saudi Arabia

Yesterday, Christian Today outlined the abuses of religious freedom that take place in Saudi, after the country's crown prince said he wanted to modernise. Freedom of religion in Saudi is 'neither recognised nor protected under the law and is severely restricted in practice'. The public practice of any religion other than Islam is banned. Its 'Basic Law' provides that the Qur'an and Sunna (the traditions of the Prophet Mohammad) serve as the constitution. The law criminalises 'the promotion of atheistic ideologies in any form', 'any attempt to cast doubt on the fundamentals of Islam', publications that 'contradict the provisions of Islamic law' and other acts deemed contrary to sharia, including non-Islamic public worship, public display of non-Islamic religious symbols, conversion by a Muslim to another religion, and proselytizing by a non-Muslim. Meanwhile, foreigners who participate in non-Muslim worship can be harassed, detained, arrested and deported. Shia Islam can be practised but Shias faced discrimination at multiple levels in the Sunni country.

Conversion is illegal and is grounds for the charge of apostasy, a crime punishable by death, though in practice the death penalty has not been carried out in recent years. Blasphemy against Islam is also punishable by death. Criticism of Islam is forbidden on the grounds of preserving social stability. The calculation of compensation for accidental death or injury differs according to the religious affiliation of the plaintiff. A Jewish or Christian male is entitled to receive only 50 per cent of the compensation a Muslim male would receive; all other non-Muslims are entitled to receive one-sixteenth the amount a male Muslim would receive. Saudi Arabia's constitution is comprised of the Qur'an and sayings of the Prophet Muhammad, which do not include religious freedom guarantees as spelled out in Article 18 of the Universal Declaration of Human Rights.