Pakistani star Ali Zafar sings for unity after Peshawar attack

Pakistan's leading singer-actor, Ali Zafar, is releasing a new song to pay tribute to the victims and survivors of the Peshawar school massacre.

The song, being released this weekend, brings together 40 of Pakistan's leading showbiz personalities and celebrities.

About 150 people, mostly children, were killed when heavily armed Taliban gunmen went on the rampage at the Army Public School in Peshawar on 16 December.

The massacre caused a deep sense of grief and disbelief in Pakistan and across the world.

"For me, it took some time to sink in that something like this could happen," says Ali Zafar. "As a parent, I felt angry and disgusted. I can't imagine the pain and anguish of the families of those children."

For several weeks after the attack, Ali struggled to move on. Performances, including a concert in South Africa on New Year's Eve, were cancelled because, as he puts it: "I just couldn't bring myself to go through with it."

He eventually decided to express his feelings and wrote the lyrics and music for the song "Urain Ge" (We Will Fly).

Taliban gunmen killed more than 150 people as they went from room to room in the school

At the start of the song, the mood is grave but as the tempo rises the music transforms into something uplifting, promising hope for a better tomorrow.

Ali Zafar is arguably Pakistan's most popular and charismatic showbiz personality. His face features on large billboard advertisements across cities and towns and on TV commercials.

'United stand'

He started his acting career in Pakistani television dramas.

In 2010, he made his debut in Indian cinema with Tere Bin Laden, a spoof film about Osama Bin Laden and a comic satire of the US "war on terror". He then went on to do films with leading Bollywood stars like Parineeti Chopra, Ranveer Singh and Govinda.

Today, the 34-year-old star has millions of fans in Pakistan, India and among the South Asian diaspora around the world.

"We don't have a choice but to take a united stand against terrorism," says Ali.

"The world needs to see that Pakistan is struggling and it is fighting. And Pakistan will rise out of this!"

Ali Zafar says Pakistan must face the truth and unite against to defeat terrorism

In the aftermath of the Peshawar massacre, Ali says he supports the apparent consensus Pakistan's leaders have reached in going after militants. "It should have happened long ago. But better late than never," he says.

For an artist in the entertainment industry, Ali is candid about his views on all that ails Pakistan.

He believes that to protect future generations, the country has to change some of its geo-strategic policies.

"We need to put our house in order. We simply cannot live in denial if we want to save this country," he says.

"The time has come for us to face the truth. We must admit to our blunders and then act, all of us together as one."

Ali plans to take his video to the Army Public School and meet students and parents there.

The proceeds from his music will go to help charities building schools and promoting education in Pakistan, he says.