ISLAMABAD: Security forces on Sunday carried out aerial strikes in Shawal Valley that killed 40 terrorists, said a statement by the Inter Services Public Relations (ISPR) – the army's media wing.

The statement said “security forces in ongoing Operation Zarb-i-Azb carried out precise aerial strikes killing 40 terrorists. Strikes were carried out in Shawal Valley.”

"There are reports of many terrorists injured in strikes", the statement said.

The area is off-limits to journalists, making it difficult to independently verify the number and identity of the dead.

The army says it is conducting the final phase of Operation Zarb-i-Azb to flush out Taliban terrorists from their remaining strongholds along the border with Afghanistan.

Read: Preliminary phase of Shawal operation successful: army.

In June a senior military official had told Dawn during a background briefing on the eve of the first anniversary of the commencement of Zarb-i-Azb that “preliminary preparations for the final push have started, which will begin next month.”

A large number of militants fleeing the operation in other parts of North Waziristan are believed to have taken refuge in Shawal Valley, which is considered to be an Al Qaeda sanctuary and a stronghold of Gul Bahadur, a warlord once considered pro-government.

Shawal has also been the focus of US drone attacks this year with multiple strikes hitting targets in the valley in which dozens of suspected militants were killed.

Pakistan Army launched Operation Zarb-i-Azb, a grand operation in the North Waziristan tribal region, following a Taliban attack on the Jinnah International Airport in Karachi in June 2014.

Since the beginning of Zarb-i-Azb, militants have fled to other tribal regions, including Khyber and its Tirah Valley and Shawal, all of which border Afghanistan.

In June this year, on the eve of the operation's first anniversary, the army said it had eliminated 2,763 terrorists during the year. There has, however, been no explanation as to how this precise figure about militant casualties has been collected because a large number of them are said to have been killed in strikes by Pakistan Air Force jets.

At that time, officials had said another 218 terrorist had been killed in intelligence-based operations (IBOs) conducted in other parts of the country to prevent the feared backlash of Zarb-i-Azb. The IBOs are flaunted by the military as a major success story.

But, this has come at the cost of 347 troops and displacement of over a million people.