Pakistan has said two Indian warplanes violated its airspace on Saturday, but that there was no cause for alarm as the incursions had been "inadvertent".
They flew up to 7.4km into the Lahore and Azad Kashmir sectors, it said.
Information Minister Sherry Rehman said Pakistan's air force remained "on alert and ready to face any eventuality, but we do not expect this to escalate".
An Indian Air Force spokesman denied the allegation, saying "there has not been any airspace violation".
Wing Commander Mahesh Upasani told Reuters news agency that the Pakistani accusations were an attempt to divert "the attention of the people towards something which has not happened".
Last week, India's foreign minister denied making a "threatening" phone call that prompted Pakistan to put its forces on alert following the co-ordinated attacks by militants in Mumbai, which left more than 170 people dead.
Pranab Mukherjee said the call was a hoax which Pakistan was using to divert attention from the fact its nationals had been involved in the attacks.
'No need for alarm'
The director of public relations for the Pakistan Air Force (PAF) said the Indian aircraft had violated Pakistani airspace on two separate occasions on Saturday.
"Both the Indian aircraft entered into Pakistan's airspace between two to four nautical miles at two different sectors," Air Commodore Humyun Viqar told Associated Press of Pakistan news agency.
He said Pakistani jets had responded, forcing the Indian aircraft to turn back.
Pakistan's information minister confirmed the incursion and said officials had "spoken to the Indian air force and they have said it was inadvertent".
"Our air force is on alert and ready to face any eventuality, but we do not expect this to escalate," Ms Rehman said. "There is no need for alarm."
Correspondents say the Indian air force has been very careful in recent years to stop its warplanes from straying into Pakistani airspace.
Two jets were shot down during the Kargil conflict in 1999, although India says they were in its own airspace at the time.