A Pakistani Frontier Corps member looks at gathered bodies of militants who were killed in a military operation in Tirah, near the Pakistan-Afghanistan border, on Dec. 19, 2014. (A Majeed/AFP/Getty Images)

A series of airstrikes and ground offensives killed at least 119 suspected militants in Pakistan’s northwestern tribal areas, officials said Friday, in a sign of intensified military action after this week’s school massacre by the Taliban.

In another display of toughening policies, two prisoners convicted of previous terrorist acts were hanged, the country’s first executions since 2008, military officials said.

Although Pakistani leaders have suggested that they could take the fight across the border into Afghanistan, the strikes remained in Pakistani territory.

But in a possibly coordinated mission, a U.S. drone strike late Thursday killed five suspected militants near Nazyan in Afghanistan’s Nangahar province, the U.S. military said. The area is where many Pakistani Taliban leaders, including chief commander Maulana Fazlullah, are thought to reside.

In all, as many as 150 suspected militants have been killed by the Pakistani air force and army since Tuesday’s slaughter at the Army Public School and Degree College in Peshawar, which claimed 148 lives, mostly teenage students.

Some students in northern Pakistan were scared to return to school Friday despite tightened security measures. An attack by Taliban gunmen on a military-run school Tuesday left 148 people dead. (Reuters)

Meanwhile, a key suspect in the 2008 Mumbai terrorist attacks was ordered held by Pakistani authorities a day after a Pakistani judge granted bail, sparking outrage in India.

The decision to block the bail order for alleged militant commander Zaki-ur-Rehman Lakhvi was widely viewed as an olive branch to India’s government as well as an effort to keep international support for sustained action against extremists.

Lakhvi has been detained in Pakistan since 2009 for his alleged role in plotting the November 2008 siege at Mumbai’s landmark Taj Mahal Palace & Tower hotel. The attack, carried out by 10 Pakistani Lashkar-e-Taiba militants, killed 166 people.

Citing a lack of evidence, a judge in Islamabad set a $10,000 bail for Lakhvi on Thursday. But a Foreign Ministry official said Lakhvi was being kept in detention under a statute allowing for the “maintenance of public order.” The government also plans to appeal the bail decision to the country’s Supreme Court.

In a further sign of widening pressure on militants, Pakistan’s powerful army chief traveled to the border region Friday to personally oversee the expanding military operation.

Pakistan’s military said that ground forces had killed at least 62 suspected militants and that 57 others had been killed by airstrikes since late Thursday. The statement said the campaign will “continue to hit these terrorists wherever they are.”

In response, the spokesman for the Pakistani Taliban, Muhammad Khurasani, gave further details of the school attack. Khurasani said a new “special-trained” group of militants was dispatched to the school’s auditorium after the group learned that students would be trained in military first aid.

1 of 50 Full Screen Autoplay Close Dec. 16, 2014 Tuesday Skip Ad × Taliban storm elite army high school in Pakistan View Photos Attack kills 132 students and nine teachers or staff members with scores more injured, Pakistani officials say. All seven terrorists were killed. Caption Attack kills 132 students and nine teachers or staff members with scores more injured, Pakistani officials say. Dec. 17, 2014 The Army Public School and Degree College in Peshawar, Pakistan, is seen the day after Taliban gunmen killed more than 140 people, many of them children. Max Becherer/Polaris For The Washington Post Buy Photo Wait 1 second to continue.

The Taliban leadership issued “clear instructions to the attackers to spare the primary section [of the school] and small kids in the other part of the school and only shoot the targeted students,” Khurasani said. “The children of army people were killed after identification. Hundreds of other innocent students were let free.”

Pakistani military leaders, however, said the vast majority of slain students were the children of civilians.

“How can I forgive those animals who destroyed the beautiful face of my innocent son?” said Palwasha Khalil, mother of a 16-year-old killed in the school. “My heart goes out when I think of how painful it was for my son to receive bullets to his head and face.”

With calls for revenge growing across Pakistan, the country’s leaders are also accelerating plans to start executing prisoners convicted of taking part in major terrorist attacks.

Prime Minister Nawaz Sharif lifted a moratorium on executions this week, and the country’s powerful army chief signed death warrants Thursday for six “hard-core terrorists.”

A senior military official said the two hanged Friday were Mohammad Aqeel, a Taliban militant involved in a 2009 attack on Pakistani military headquarters in Rawalpindi, and Arshad Meherban, who was convicted of attempting to assassinate Pakistan’s then-president, Pervez Musharraf, in 2003.

The official spoke on the condition of anonymity because he was not authorized to make public comments on the executions.

Pakistani government leaders also are rushing to review the cases of hundreds of other prisoners who have been convicted of terrorism in civilian courts over the past decade.

The Interior Ministry has identified more than five dozen prisoners who have exhausted their appeals and could face execution in the coming weeks.

The Pakistani Taliban, meanwhile, warned that it will kill even more children if the government follows through with the planned executions.

“The rulers should prepare for the worst possible reaction should they act with executions,” Khurasani said.

In another potential flash point, protesters in Islamabad marched for a second consecutive night near the Red Mosque, where a bloody government crackdown against Islamic student radicals in 2007 helped lead to the creation of the Pakistani Taliban.

Chanting “a friend of the Taliban is a traitor” and “Taliban are child killers,” the demonstrators demanded the arrest of the mosque’s cleric, Maulana Abdul Aziz, who appeared unwilling to condemn the Taliban attack during a television interview.

“This person is the father of the terrorists,” said protester Zafar Ullah, 39. “This attack has become the critical point where people feel it in their heart and soul, erupt and come to the streets.”

Haq Nawaz Khan and Aimar Iqbal in Peshawar contributed to this report.