A child was among at least six people killed in a double suicide bombing targeting a court in Pakistan amid a wave of terror attacks by Isis and the Taliban.

Three militants threw hand grenades and opened fire as they launched the assault in Tangi, near the border with Afghanistan, on Tuesday morning.

Two of the men blew themselves up during the 20-minute gun battle with security forces at the gate, while the third was shot dead by police before he could detonate his explosive vest.

More than 80 people killed in a Pakistan terror attack

Ijaz Khan, chief of the district police, told Reuters: “The terrorists had come and wanted to kill as many people as they could inside the judicial complex.”

They were prevented from entering the building but killed five people in the assault – a child, a lawyer and four police officers – and injured dozens more.

​Mohammad Shah Baz Khan described scenes of panic during the battle, saying several people scaled the complex’s walls in efforts to escape.

"Lawyers and other people in the complex started running to save their lives. There was panic and nobody knew where to go," he said.

Police had been on high alert after receiving intelligence that terror groups could target courts in Charsadda, Khyber Pakhtunkhwa province, following similar attacks elsewhere in Pakistan.

More than 100 people have been killed in a wave of atrocities that started last week, including an Isis suicide bombing that killed at least 90 people at a Sufi shrine on Friday.

A propaganda statement by Jamaat-ul-Ahrar claiming to show two suicide bombers that attacked a court in Pakistan on 21 February

Jamaat-ul-Ahrar, an affiliate of the Pakistani Taliban, has also launched numerous bombings and attacks after announcing the start of a new campaign of violence against the government, security forces, the judiciary and secular political parties.

The group claimed responsibility for the court attack via Taliban propaganda channels, issuing a statement in Urdu claiming “apostates were sent to hell by martyrdom fighters”.

Jamaat-ul-Ahrar published a photo of the two militants who detonated their bombs, who appeared to be teenage boys.

There were rumours the group had pledged allegiance to Isis after it split of the Taliban and expressed support for the so-called Islamic State, but the faction has now formally re-joined its parent group.

Pakistan's army chief General Qamar Javed Bajwa praised police for "saving many lives" in the group’s latest attack, according to the military statement.

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Zafar Iqbal Jhagra, the governor of Khyber Pakhtunkhwa province, told reporters that fresh talks with the militants cannot be ruled out.

"Talks can be held with everyone, including the Taliban," he added. "[But] we will not bow before the terrorists."

Isis’ shrine bombing, the deadliest terror attack in Pakistan for years, was followed by a nationwide crackdown by the military that resulted in the deaths of more than 100 alleged “terrorists” in 24 hours.

The operation sparked warnings from humanitarian groups for Pakistani authorities to adhere to international law.

The violence has also worsened relations between Afghanistan and Pakistan, who have accused each other of harbouring terrorists and each sent lists of named militants allegedly residing in the neighbouring country.