ISLAMABAD/NEW DELHI - Flight operations at airports of major cities of Pakistan have been temporarily suspended due to operational reasons, the Pakistan Civil Aviation Authority (PCAA) said on Thursday.

The PCAA officials told Xinhua that flight operations at Allama Iqbal International Airport in Lahore, Jinnah International Airport in Karachi, Islamabad International Airport, and Sialkot International Airport will remain suspended until further notification.

The PCAA said that air routes will be unavailable for commercial flights, advising the passengers to stay in touch with relevant airlines for the latest situation.

Earlier on Thursday morning, four people were injured when a blast occurred at a military compound in Lahore, the capital of Pakistan's eastern Punjab province, official sources told Xinhua.

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Official sources from Pakistan also said two people were injured when an Indian drone crashed near a gas well in southern Sindh province on Thursday morning.

On the same day, Pakistani authorities also reported shooting down drones in the Lahore and Chakwal districts of eastern Punjab province.

The Pakistani army's media wing on Wednesday said 31 people were killed and 57 others injured in an Indian attack on Pakistani territory and subsequent exchange of fire between Pakistani and Indian troops along the LoC, the de facto border that divides the disputed region of Kashmir.

India carried out large-scale "ceasefire violations" in border areas throughout the day on Wednesday, following attacks on houses and mosques that targeted civilians in Pakistan-controlled Kashmir and the eastern Punjab province during Tuesday night and the early hours of Wednesday morning, Director-General of the Inter-Services Public Relations (ISPR), Lieutenant General Ahmed Sharif Chaudhry, told the media during a briefing.

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He stated that Pakistan responded effectively by targeting an Indian brigade headquarters, a battalion headquarters, and multiple military posts across the LoC in the Kashmir region, and along the working boundary between Pakistan's Punjab and India-controlled Kashmir during the day-long exchange of fire.

The ISPR chief said that Indian jet fighters struck six locations within Pakistani territory, but the Pakistani Air Force responded by shooting down five Indian fighter jets with precision.

In addition, the Pakistani army shot down seven Indian spy and combat drones and captured two more using advanced technology, he added.

"We were well-prepared. Pakistan did not suffer any combat casualties during the exchange of fire, and the Air Force did not lose any aircraft or assets in the strikes," he said.

India had accused Pakistan of hosting terrorist camps, but after Pakistan invited both local and foreign media to inspect the alleged sites, India launched a surprise night-time attack on those locations, he added.

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Pakistan reserves the right to respond in self-defense at a time of its choosing, he said, adding that the country's commitment to peace should not be mistaken for weakness.

While Pakistan seeks regional stability, it will not hesitate to act decisively if provoked, Chaudhry said.

Meanwhile in India, local media reported that at least 15 civilians were killed and over 50 others wounded on Wednesday in the clashes.

According to state-run broadcaster All India Radio (AIR), 15 civilians were killed after Pakistani troops initiated artillery firing in frontier districts.

Officials said all the deaths were reported from the worst-hit Poonch district, 185 km southwest of Srinagar city in Indian-controlled Kashmir. Forty people were also wounded and dozens of houses and vehicles were damaged.

Apart from this, 10 people, including five minor children, were wounded in cross-border shelling in the Uri sector of Baramulla district, while three others were wounded in Rajouri district.

Indian army officials said they were effectively responding to the shelling and firing from the Pakistani side.

Wednesday marks the 13th straight day of ceasefire violations on the LoC, according to the Indian side.

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Indian media reported that three unidentified aircraft, two in Indian-controlled Kashmir and one in Punjab, were found crashed. So far, there are no official comments on the crashes.

Reports said over 200 flights were cancelled and 25 airports temporarily shut down across northern and western India on Wednesday due to the prevailing situation.

Meanwhile, mock drill exercises were conducted in several parts of India to evaluate civil defence preparedness. This was the first nationwide exercise at such a scale in the past several decades, according to media reports.