Britain on Tuesday began evacuating its citizens from Sudan, after criticism of a delay in getting its passport holders out of the restive country.

"The first flight has left and you can expect that there will be at least two more flights overnight tonight," Prime Minister Rishi Sunak's official spokesman told reporters.

Britain only announced that it had launched a large-scale evacuation on Tuesday morning, lagging other countries and 10 days since fierce urban fighting erupted, leading to hundreds of deaths.

After paying nearly $100,000 in ransoms to free 10 family members, Khaled Taalou, a member of Iraq's Yazidi minority, is still working to free other missing relatives kidnapped by Islamic State group fighters.

Despite his efforts, five more relatives, along with thousands of other Yazidis, remain missing after being abducted by the jihadists.

"We are still looking. We do not lose hope," the 49-year-old said.

Clutching overstuffed suitcases, bleary-eyed civilians described a harrowing escape from violence-wracked Sudan across the Red Sea to Saudi Arabia, sobbing at memories of air strikes and urban combat.

Elderly women in wheelchairs and babies asleep in their parents' arms were among nearly 200 people from 14 countries who disembarked from a naval frigate in the coastal city of Jeddah on Monday night after daring –- and draining –- journeys to safety.

The United Arab Emirates' Hope space probe on Monday revealed Mars' smaller moon Deimos in unprecedented detail, shedding new light on the origin of the mysterious lumpy satellite.

The probe, the Arab world's first interplanetary mission, has been orbiting Mars for two years, regularly flying past Deimos and its big sibling moon Phobos.

It came within 110 kilometres (68 miles) from Deimos, a rocky object the shape of a bean just 12 kilometres wide, according to the Emirates Mars Mission (EMM).

A resident of Israeli-annexed east Jerusalem wounded on Monday five pedestrians in the city centre before being shot dead, in what Prime Minister Benjamin Netanyahu called a "terrorist attack".

The Magen David Adom emergency service said those hurt included a 70-year-old man who was left in a "serious condition", as well as a 30-year-old woman.

Police said the driver, a man in his 30s, was a resident of Beit Safafa, a Palestinian neighbourhood in east Jerusalem.

A US-brokered ceasefire between Sudan's warring generals entered its second day Wednesday but remained fragile after witnesses reported fresh air strikes and paramilitaries claimed to have seized a major oil refinery and power plant.

"The pause was not fully upheld, with attacks on headquarters, attempts to gain ground, air strikes, and explosions in different areas of the capital," UN Special Representative Volker Perthes told the Security Council Tuesday.

Ibrahim Mohamed turned in his hospital bed to find the patient next to him had died, but fighting that had erupted in Sudan's capital hours earlier meant the body could not be moved.

Battles since April 15 between the forces of two rival generals have turned Khartoum into a war zone, shuttering hospitals and preventing health professionals from providing care.

By the time Mohamed, a 25-year-old leukaemia patient, was finally evacuated from the Khartoum Teaching Hospital on Tuesday, the body was still there.

At a school in Amman, a Jordanian volunteer opened a book and asked: "Who's excited to hear a story?" -- part of an initiative to get children to find joy in reading.

The "We Love Reading" initiative, which is present in 65 countries worldwide, was founded by Rana Dajani, an associate professor of biology and biotechnology at the Hashemite University in Jordan.

She spent five years living in the United States, where she enjoyed reading to her children.

But when she returned, Dajani noticed schoolchildren in her home country were rarely reading for pleasure.

Multiple nations have scrambled to evacuate embassy staff and citizens by road, air and sea from chaos-torn Sudan, where fighting between the army and paramilitaries has killed hundreds.

Rescue operations intensified Tuesday as a 72-hour ceasefire took effect, but gunfire still rang out in Khartoum.

According to an AFP tally, more than 6,400 people have left Khartoum in the foreign-led evacuations. Here is an overview of what nations have done to get stranded citizens to safety.

- Mideast and Africa -

Heavy fighting in Sudan, which has plunged the nation into chaos and killed hundreds, has also raised fears about the fate of 25 lions and other animals in a wildlife reserve.

The facility said it is without electricity to power safety fences around enclosures and running low on food for the felines, which each require five to 10 kilogrammes (11 to 22 pounds) of meat a day.