PATHANKOT: Indian forces have killed the last of the six militants who attacked an air force base near the Pakistan border over the weekend, the defense minister said Tuesday, though soldiers were still searching the base as a precaution.

Manohar Parrikar stopped short of saying the operation had ended, but Indian officials have said repeatedly that only six gunmen were involved.

At least twice over the weekend it appeared that the attack had ended but fresh gunfire and explosions erupted both times.

Parrikar did not explain how just a handful of gunmen managed to paralyse a large Indian air base for almost four days, insisting that security forces had done “a commendable job.”

Seven Indian soldiers were killed during the attack.

“I see some gaps (in intelligence) but we will be able to understand only after the investigation. But I don't think we compromised on security,” he told reporters after touring the scene of the fighting.

He noted that the base is large, and is wooded in some places, making it difficult to pin down the gunmen.

Parrikar said the militants' weapons included AK-47 assault rifles with makeshift rocket launchers attached, mortar rounds that could be fired from the launchers, pistols, and 50-60 kilograms (110-130 pounds) of ammunition.

A fifth gunman was killed Monday on the third day of a siege.

There was no gunfire as troops searched the air base on the fourth day of the siege looking for a possible sixth gunman involved in the attack.

Earlier, Indian Air Force spokeswoman Rochelle D'Silva had said, "There has been no firing since Monday night at the base."

The search operations at Pathankot air force base will continue until all areas have been completely secured, Maj Gen Dushyant Singh, from India's elite National Security Guard, told reporters.

The attack has dragged on since early Saturday morning as government troops struggled to contain the heavily armed attackers.

Four attackers were reported killed by Saturday evening, and at least two were said to have been exchanging gunfire with troops as of Monday morning. By evening one had been shot dead, Singh said.

Defence officials have said authorities had been alerted about a potential attack in the area on Friday, and that aerial surveillance at the base spotted the gunmen as they entered the compound, leading to criticism of the handling of the situation.

Singh told reporters in Pathankot that it will take a "long time" to declare the base completely secure because of its size and geography. It is spread over more than 2,000 acres, including forests and tall grass.

The commanding officer of the base, Lt Col JS Dhamoon, described it as a "mini-city" with homes and a school for the children of the personnel stationed there.

An army statement had earlier said the last gunmen were firing from a building that is part of the living quarters on the base.

The base has a fleet of India's Russian-origin MiG-21 fighter jets and Mi-25 and Mi-35 attack helicopters, along with other military hardware. Officials have said no military hardware has been damaged in the fighting.

Military funerals were held Monday for the soldiers who were killed in the attack. Their killings inside a military base despite intelligence alerts have angered many in India.

"The biggest problem is the multiplicity of command and control. Nobody knows who is really in charge," said Rahul Bedi, an analyst for Jane's Information Group.

The Pathankot base and the northern state of Punjab, where it is located, has "probably the highest concentration of military personnel in India because it's so close to the border with Pakistan," Bedi said. "It's a huge embarrassment," he said. "It's a major goof-up for everybody."

Since Saturday morning, the base has been swarming with air force commandos, army soldiers, National Security Guard troops and local police.

Editorial: Attack on Pathankot air force base

Officials, however, have refused to say how many security personnel were involved in the engagement.

The base is on the highway that connects India-held Kashmir (IHK) with the rest of the country. It is also very close to the shared border with Pakistan.

An alliance of Kashmiri militant groups, the United Jihad Council (UJC) on Monday claimed responsibility for the attack.

The UJC in a statement said that the attack was a message to India that Kashmiri fighters could strike at any sensitive installation across India.

"Pathankot air base attack has been carried out by the mujahideen associated with National Highway Squad," said Syed Sadaqat Hussain, a spokesman for UJC.

"Pakistan has nothing to do with the attack but ironically the Indian government, media and their armed forces are suffering from Pakistan phobia," added the UJC spokesman.