Pakistani police have sealed off a house in the city of Rawalpindi amid reports of an attempt to shoot down President Pervez Musharraf's plane.
President Pervez Musharraf survived two attacks in 2003
Reports say the house was under the flight path of Gen Musharraf's plane.
A photographer for the Reuters news agency said there were two large guns mounted on the roof of the house.
A military spokesman denied any firing had taken place. Gen Musharraf's travel plans are highly secret. He has survived two assassination attempts.
In addition, the authorities say they have foiled at least three other conspiracies to kill him.
'Sound of gunfire'
The president was flying from the Chaklala air base in Rawalpindi, a garrison town close to the capital, Islamabad, to see flood damage in Balochistan province.
Security officials examine an anti-aircraft gun on the house roof
He arrived safely, officials say.
People living near the house in Rawalpindi say they heard shots being fired.
"We heard the sound of gunfire," Mohammed Ishraq told the BBC's Urdu service. "When we arrived here we heard that it was some sort of terrorism."
Another man, Ishaq Ahmed, said: "Everyone heard a firing sound. The firing sound was like a bomb blast. It was that kind of sound."
An anti-aircraft gun and a light machine gun, as well 100 rounds of ammunition and two satellite antennas from the residence have been recovered from the house, Deputy Inspector General of police Marwat Ali Shah told the BBC.
Publicly officials flatly reject there was any attempt on Gen Musharraf's life.
"There was no firing at the president's plane. He is in Turbat [in Balochistan]," an army spokesman said.
The incident comes amid anger among many in Pakistan at Gen Musharraf's decision to take on Islamic radicals at the Red Mosque in Islamabad.
The confrontation there has so far resulted in 19 deaths.
Meanwhile, at least four soldiers have been killed in a suicide bomb attack in North West Frontier Province (NWFP), local officials say.
Two of them were officers.
The incident took place in the town of Chakdara, some 200 kilometres north of the NWFP capital, Peshawar.
Reports say the attacker threw himself at an army jeep.