New Delhi, Jan 2 (IANS): In the wake of a terrorist attack on the Indian Air Force (IAF) base in Punjab early Saturday, Congress questioned the rising number of terror incidents in the state after 20 years of calm.

"Why has Punjab suddenly become the hotbed of terror activities in the last few months? The state has been calm for last 20 years," Congress spokesperson Randeep Surjewala said.

"Prime Minister (Narendra Modi) should ensure that there is no repetition of such attack in future," Surjewala told a private news channel.

The statement came after four to six armed terrorists, wearing army fatigues, attacked the IAF base in Pathankot district at around 3 a.m., prompting a fierce gun battle with security forces till around 8 a.m. that left four terrorists killed.

Combing operations were launched to find out any other terrorists hiding anywhere. Firing and grenade blast were heard from the base after a lull of around three hours.