Umar Fidayee, 14, said the would-be bombers were being trained in North Waziristan.

He made the remarks in an interview aired Friday from his hospital bedside, where he is being treated after detonating a hand grenade in the April 4 attack that killed 50 people at a 13th-century Sufi shrine.

Fidayee said: “I was blindfolded by my captors and brought to Dera Ghazi Khan to attack the shrine.”

He said he was a schoolboy and was taken to Waziristan by force.

According to AFP, police arrested Fidayee as an alleged accomplice and said they removed his own suicide vest, which he failed to detonate in a crowd of hundreds in Dera Ghazi Khan just minutes after two other bombers blew themselves up.

Shown covered in tubes and bandages, the teen appeared to express remorse and lifted the lid on harrowing details of his training at the camp in the Mir Ali district of North Waziristan, which lies on the border with Afghanistan.

“Three hundred and fifty to 400 would-be suicide bombers are getting training in Mir Ali in North Waziristan,” he said in the interview broadcast by Pakistani television channels Samaa, Express, ARY and Geo.

“I was trained for two months and saw many boys being trained there,” he said, going on to appeal on Pakistanis to “please forgive me.” He said: “God has given me a new life but I am sad that we killed innocent people, innocent children.” Fidayee said he was initially recruited on the understanding that he would be smuggled into Afghanistan to kill non-Muslims.

“But they brought me here to Dera Ghazi Khan. I told them ‘there is no kafir (non-believer) here’,” he said. “They told me these people are worse than kafirs,” Fidayee said.

Exposing an apparently disturbing recruitment at the gates of an ordinary school in North Waziristan, the teenager claimed a man he identified as Qari Zafar convinced him to begin a life of militancy, AFP reported.

“He told me that all this education is useless and said ‘become a fighter and you will go to heaven’,” Umar told the reporters.

He said the bombers arrived in Dera Ghazi Khan five days before the bombing, checked into a local hotel and conducted two reconnaissance missions to the shrine 480 km southwest of the capital Islamabad.

“A man called Ayyaz gave us the suicide jackets on April 3 (the day of the attack). At 4 or 5 p.m. we visited the Sakhi Sarwar shrine and he told us each where to carry out our attacks,” Umar said.

They used a rickshaw and public minibus to travel to the site and the teen said it was his job to attack 30 minutes after the other two, to cause maximum carnage among those helping with the rescue efforts.

In a message to other potential suicide bombers, he said: “Please refuse to carry suicide attacks. Such attacks are forbidden in Islam.”