Pope Francis has demanded protection for Pakistani Christians as he condemned a suicide attack in Lahore that killed at least 70 on Easter Sunday.

The Holy Father addressed thousands in St Peter's Square, Rome, on Monday as he branded the attack "vile and senseless". He said Easter had been "bloodied by a hideous attack that massacred so many innocent people, mostly families of the Christian minority".

A breakaway Taliban militant group that once declared loyalty to Islamic State claimed responsibility for the blast. In a statement after the attack Jamaat-ul-Ahrar said they had targeted Christians.

The pope was speaking from the window of the Vatican's Apostolic Palace for his Regina Caeli address on Easter Monday.

"I appeal to civil authorities and all sectors of that nation to make every effort to restore security and serenity to the population, and in particular to the most vulnerable religious minorities," he said.

"I repeat once again that violence and murderous hatred only lead to pain and destruction; respect and fraternity are the only path to achieving peace."

The chairman of the British-Pakistani Christian Association, Wilson Chowdhry, told Christian Today he believed the government should have done more to predict the attack and protect Christians. Pakistan has over 2 million Christians who make up less than two per cent of its Muslim majority population.

Pope Francis, urged those gathered to pray that God would "stop the hands of the violent ones who sow terror and death".

Additional reporting by Reuters.