The Pakistan Airports Authority (PAA) issued a new Notice to the Airpersons (NOTAM) on Thursday announcing that Lahore's airspace has been closed once again.

The airspace has been closed till 6am tomorrow morning, according to the Notam by PAA.

Additionally, new instructions were also issued for Gilgit and Skardu airports. 

Both the airports have been advised by the PAA to coordinate with air traffic control before the operations of flights. Without clearance, flights will be banned at Skardu and Gilgit airports, the PAA said.

Earlier, PAA announced that flight operations have resumed at the Lahore, Islamabad, and Sialkot airports.

Passengers are advised to stay in contact with their respective airlines for the latest information regarding their flights, the PAA added.

However, there was no clarity about Karachi's situation.

The PAA earlier suspended flight operations at Lahore, Karachi, Islamabad and Sialkot airports, amid the current tension between Pakistan and India.

The authority first announced closure of the airports till 12pm today, then the period of closure was extended till 6pm.

According to the PAA, flight operations were temporarily suspended due to operational reasons.

The authority took the decision amid heightened threats of India's forces trespassing in the Pakistani airspace.

Furthermore, several, mostly Asian airlines, announced that they were cancelling and rerouting some flights following Indian strikes into Pakistan's territory, escalating the crisis between the nuclear-armed neighbours.

Images from flight tracking websites after the attack showed a long line of airlines passing over Oman, the United Arab Emirates (UAE) and Kuwait, raising the possibility of airspace congestion.

Pakistani authorities said 57 international flights were operating in Pakistan's airspace when India struck.

Prime Minister Shehbaz Sharif's office said in a statement that India's action "caused grave danger to commercial airlines" belonging to Gulf countries and "endangered lives."

Earlier on Wednesday night, the PAA confirmed that all the airports were functioning normally across the country after the national airspace was closed for a few hours

Pakistan had suspended flight operations at major airports following India’s attack inside the country on Tuesday-Wednesday night.

Pakistan armed forces, in response to Indian aggression, shot down five Indian Air Force (IAF) jets, a combat drone, and destroyed brigade headquarters after India carried out missile strikes in cities of Punjab and Azad Kashmir.