Pakistan’s Speaker of the House of Representatives, Asad Qaisar, returned to Islamabad on Thursday after the plane he was traveling in turned back from Afghanistan due to security threats.

Pakistan’s Ambassador to Afghanistan Mansoor Ahmad Khan said the aircraft was already in Afghanistan airspace when it turned back.

Khan said the plane was turned back after NATO warned they had found explosives on the runway at Hamid Karzai International Airport in Kabul city.

Qaisar had been scheduled to arrive in Kabul on Thursday on a three-day visit.

“When the speaker of the Pakistani parliament landed [back] at Islamabad airport, the two sides talked and Asad Qaisar said he understood the situation in Afghanistan and would travel to Afghanistan soon,” said Khan.

NATO forces reportedly warned officials of explosives on the runway. However, members of the Wolesi Jirga (Afghanistan’s Lower House of Parliament) said it would investigate the incident.

“Members of the House of Representatives and the Administrative Board were present, the decision is that this issue will be reviewed by a committee later, but for now, NATO forces have canceled the trip due to security threats,” said Abdul Qadir Zazai Watandost, Wolesi Jirga Secretary.

However, security officials at Hamid Karzai International Airport say all flights into and out of Kabul were postponed for several hours after they received a warning from NATO forces.

According to the officials, explosives had been planted on one of the runways years ago.

“Forty minutes ago, the coordination department announced that NATO forces had discovered explosives at the airport on one of the runways during construction work, which is why all flights have been canceled,” said Reyaz Arian, the commander of Hamid Karzai International Airport in Kabul.

“The safety of all people is our priority, as long as there is a threat, no plane will be allowed to land,” said Toryalai Takal, airport operations officer.