Kate Middleton and Prince William's plane was forced to abort its landing after a terrifying electrical thunderstorm hit Pakistan.
The plane was returned to Lahore after it made two failed landings at Islamabad International Airport.
The RAF Voyager circled the country's capital for around an hour before heading back to its original take-off point 25 minutes away, according to reports.
The flight was meant to take about 25 minutes, but the plane was in the air for two hours.
Lightning was also seen crashing around the right wing of the plane as it bumped and rolled around due to the serious turbulence, one eyewitness said.
Prince William confirmed he and his wife Kate were fine following the ordeal.
The aircraft was also carrying journalists and other members of royal staff who were left shaken by the incident.
One passenger said it was a "pretty serious storm", describing the flight as a "rollercoaster".
"It was pretty hairy at times," another said.
"The plane was making large jerking movements as we tried to battle through the wind.
"It was a relief to land safely in Lahore."
William asked travelling media if they were okay following heavy turbulence and joked: "I was flying!"
The RAF Voyager has been vacated while it refuels at Lahore airport.
A senior civil aviation official in Lahore said the couple could try again to fly to Islamabad later on Thursday if weather permitted, or else they would stay in Lahore.
The Duke and Duchess are on a five-day visit to Pakistan but are not being accompanied by their children.
The Mirror's Ian Vogler who is part of the travelling press pack on the RAF Voyager with the royals said: "We made two landing attempts one at the military airport one at the civilian after a massive thunderstorm which sent the plane shaking with severe mid air turbulence."
Earlier today, William and Kate were given a tour of the Badshahi Mosque holy site in Lahore.
They also walked on a red carpet through the holy building with the imam before being given a tour of the inside, where they heard a Koranic verse.
The couple were invited to sit down cross-legged after being introduced to a group of scholars and religious leaders, who were sitting on cushions, for a discussion on promoting interfaith harmony among communities.
We'll be bringing you the very latest updates, pictures and video on this breaking news story.
