Authorities in Pakistan were looking for a gunman who opened fire at a plane Tuesday evening just as it was landing in the volatile northwest, killing one person and wounding two others, officials said, casting fresh doubts about security at the country's airports.

The violence in Peshawar comes just two weeks after gunmen laid siege to the country's busiest airport in Karachi in an attack that shocked Pakistanis and the international community and helped trigger a long-awaited military offensive against militants in the northwest.

A female passenger on board the plane died on the way to the hospital, said Mashood Tajwar, a spokesman for the national carrier, Pakistan International Airlines. He said 178 passengers and an undetermined number of crew were on board.

Two other people on the flight were also wounded, said Dost Muhammad Khan, the station house officer in charge of the area. The plane was coming from Riyadh, Saudi Arabia, said Khan and the passengers were believed to mostly be Pakistanis who go to Saudi Arabia to work. He said the woman had been visiting her husband and had also gone on a religious pilgrimage.

"When the plane was about the land, we heard shots and suddenly there was chaos in the flight," said an unidentified male passenger, speaking to Dunya TV outside the airport.

Khan initially said five bullets hit the plane as it was coming in to the airport, but the Senior Superintendent of Police, Najeeb ur Rehman Bhagvi, said when he and other authorities later inspected the plane they found at least ten bullet holes.

The plane was about 300 feet off the ground when someone opened fire on it from below with a sub-machine gun or an AK-47, Bhagvi said.

Authorities were scouring the area around the airport to find whoever is responsible, Khan said.

There was no immediate claim of responsibility but suspicion will likely fall on militants that the government has been fighting in the country's northwest.

The Pakistani Taliban has been attempting for years to overthrow the government and establish their hardline form of Islam across the country.

Peshawar is located on the edge of the tribal regions where militant groups such as Al Qaeda and the Taliban are based and over the years the city has become a frequent target of bombings and shootings.

The Peshawar airport has a military and civilian side. In Dec. 2012 suicide bombers armed with rockets attacked the military side of the airport, killing four civilians.

After the Karachi airport assault, the military announced a major operation on June 15 against militants who have been using the country's North Waziristan tribal area as a safe haven from which to launch attacks against targets in Pakistan as well as Afghanistan.

The U.S. had been pushing the government and military to clear the area of militants since groups such as the Haqqani network and others used North Waziristan as a base strike at NATO and Afghan troops.

Hundreds of thousands of refugees have poured out of North Waziristan since the operation started, although so far it has mostly consisted of airstrikes against militant hideouts.

People across Pakistan have been bracing for reprisal attacks ever since the operation got under way.

The operation came after the Pakistani Taliban and an Uzbek militant group attacked the airport in the southern port city of Karachi. During the audacious attack, gunmen battled with airport security and other law enforcement authorities for roughly five hours.

The mayhem shocked the country and raised questions about the security of other airports around Pakistan.