India and the United States have blamed Pakistan-based militant group Lashkar-e-Taiba for the Mumbai attacks, which killed at least 180 people, leading to a sharp rise in angry rhetoric between the nuclear-armed countries which have fought three wars.
Pakistani media attributed its reports to military sources, who were confirming that all three armed forces including the navy, air force and army were on red alert, according to Kamal Hyder, Al Jazeera's correspondent in Pakistan.
"The Pakistani air force have been seen visibly in a number of locations flying close to the Pakistani-India border in what is being described as an aggressive patrolling mode, following reports that India is planning pre-emptive strikes against locations in Pakistan, " the reporter said.
Observers are saying that the Congress party in India has lost a great deal of prestige due to the Mumbai attacks and therefore may try a show of strength in Pakistan, said Hyder.
Meanwhile, the Reuters news agency quoted a Pakistan airline official as saying the Pakistani air force conducted an exercise yesterday causing delay of two civilian flights.
"Two of our flights were delayed for some time because the PAF was conducting some exercises but now everything is back on normal," said Muhammad Latif, a spokesman for the airlines. The flights were delayed at the airport in the eastern city of Lahore, near the Indian border, Latif said, while dismissing television news channel reports of a high alert at Pakistani airports. "In the current environment, PAF has enhanced its vigilance," chief air force spokesman Air Commodore Humaun Viqar Zephyr told Agence France-Presse.
Residents in the capital Islamabad, the nearby garrison city of Rawalpindi and the eastern city of Lahore made panicked telephone calls to media outlets to ask about the low-flying fighter jets.
In another development yesterday, India’s foreign minister criticized the international reaction to last month's attacks on Mumbai, saying pressure put on Pakistan by world leaders was inadequate. "There has been some effort so far by the international community but this is not enough," Agence France-Presse news agency quoted Mukherjee as saying.
Asked whether a military response to the attacks was being considered, Mukherjee said India would "explore all options" to push Pakistan on its promise to crack down on cross-border terrorism.