A UN-mandated group of experts has urged warring parties in Yemen to release detainees and political prisoners to minimize the risk of COVID-19 in the conflict-ravaged country as fighting continues despite an initial ceasefire agreement.

"Prisoners and detainees in Yemen are particularly vulnerable and exposed to substantial risk if the COVID-19 virus was to emerge in prisons and other detention facilities," said the Group of Eminent International and Regional Experts on Yemen in a statement on Monday, describing conditions behind bars as "appalling."

Crammed quarters, lack of proper sanitation and inadequate access to health care services "are exposing detainees to a high risk of death in case of COVID-19 infection."

"Necessary physical distancing and self-isolation will be impossible," the statement read.

The committee's calls echo a fresh appeal by the UN High Commissioner for Human Rights Michelle Bachelet to governments not to forget about people in incarceration during the pandemic.

"It is vital that governments should address the situation of detained people in their crisis planning to protect detainees, staff, visitors and of course wider society," Bachelet said in a recorded statement last week. "Now, more than ever, governments should release every person detained without sufficient legal basis," she added.

Several countries have moved to temporarily release or altogether pardon some offenders to ease pressure on correctional facilities and curb the spread of the coronavirus.

In early March, Iranian authorities announced they are temporarily freeing over 70,000 prisoners and on Sunday, they extended furloughs for 100,000 prisoners. In Syria, President Bashar al-Assad has issued amnesty and reduced sentences for several crimes to ease congestion that risked spreading the virus. Libya over the weekend also released 450 inmates and promised other measures to "reduce the overpopulation of prisons."

Further afield, authorities in Northern Ireland have announced that fewer than 200 prisoners could be eligible for early release, while the Scottish government said it's going over similar options. Pregnant inmates in the UK will soon be sent home to protect them from infection. Across the pond, facilities in New York City, Los Angeles, and California are also cutting down the number of inmates.

No cases have been reported in Yemen so far, but experts are warning that an outbreak there could be catastrophic as a years-long conflict has razed medical infrastructure and left 24 million people – a whopping 80 percent of the population – in need of humanitarian assistance.

Renewed violence over the weekend is also risking hindering efforts to prepare for a possible viral outbreak in the country.

UN Chief Antonio Guterres last week called for guns to be silenced around the world to allow the international community to focus its efforts on the coronavirus pandemic. "It is time to put armed conflict on lockdown and focus together on the true fight of our lives," he said.

His appeal was initially welcomed by the warring sides in Yemen, with reports that Saudi Arabia, which backs the government of Yemeni President Abed Rabbo Mansour Hadi, and Houthi rebels agreed to a truce.

But the respite was short-lived, with Saudi authorities saying on Saturday they intercepted ballistic missiles over Riyadh, which they blamed on the Houthis. On Monday, the Riyadh-led coalition fighting the Iran-backed group carried out several raids targeting "legitimate military targets including Houthi ballistic batteries which threaten civilian lives" in the capital Sanaa.