Mohammed bin Salman, Saudi Arabia's 32-year-old crown prince, will visit the UK from March 7 on an official trip, according to Downing Street sources.

A spokesperson for Theresa May, the UK's prime minister, said the meeting will tackle international challenges, such as "terrorism, extremism, the conflict and humanitarian crisis in Yemen and other regional issues such as Iraq and Syria".

Since the Saudi-led military intervention started in Yemen in March 2015, the Arab world's poorest country has found itself on the brink of a devastating humanitarian crisis, with the UN warning of widespread famine and spread of disease.

British arms companies are some of the biggest suppliers of weapons to Saudi Arabia, and the British government has approved billions of pounds in export licences over the past three years.

Rights groups have repeatedly condemned the Saudi-led coalition over civilian casualties in Yemen, but the UK has yet to take any punitive measures against Riyadh.

An official visit by Mohammed bin Salman (also known as MBS) had been anticipated for weeks, prompting groups such as Stop the War Coalition, the Campaign Against Arms Trade, and the Arab Human Rights Organisation to petition May to withdraw an invitation to the crown prince.

In the kingdom, Mohammed bin Salman is credited with leading a series of social reforms, such as allowing women to drive and lifting a 35-year ban on cinemas.

However, activists say Saudi Arabia still has a poor human rights record and have warned against interpreting these reforms as heralding new freedoms.

"Mohammed bin Salman's long overdue reforms in Saudi Arabia must not be used to mask the ongoing crackdown on the exercise of fundamental rights," Reprieve, a UK-based rights group that campaigns against the death penalty, said on Tuesday.

Over the past few years, the kingdom has sentenced several protesters to death.

"Since his appointment as crown prince, the final death sentences of protesters, including a number who were children at the time, have been confirmed amid serious allegations of torture and an unprecedented number of executions," Reprieve said, calling on May to demand that Saudi Arabia abolish capital punishment for protest-related offences.

"The close relationship Theresa May trumpets has led to British police officers training Saudi agents in the kind of cyber-monitoring techniques which have been used to justify death sentences," Reprieve said.

By Tuesday, more than 11,000 people had signed an online petition calling on May to cancel the crown prince's visit.