Image copyright AFP Image caption Many of the bomb victims were children at a funfair in the Lahore park

More than 200 people have been detained in Pakistan in the hunt for those behind the Easter Sunday bombing that killed at least 72 people in Lahore.

Punjab's law minister said those held were among more than 5,000 questioned in a sweeping counter-terror offensive.

Weapons and ammunition have also been seized in raids by security forces.

Taliban splinter group Jamaat-ul-Ahrar said it carried out the attack against Christians celebrating Easter, although most of those killed were Muslims.

Pakistan's counter-terror offensive

The area around Gulshan-i-Iqbal park was more crowded than usual, as members of Lahore's minority Christian community had gathered to celebrate Easter at a funfair there.

At least 29 of the victims were children. Another 300 people were injured, with officials saying they expected the death toll to rise.

"There are no militant safe-havens or no-go areas in Punjab," law minister Rana Sanaullah told a news conference in Lahore.

He said 56 intelligence operations had been jointly carried out by police, paramilitary, army and intelligence forces.

Image copyright AFP Image caption Dozens of children were among the dead

Media playback is unsupported on your device Media caption The BBC's Shaimaa Khalil reports on distressing scenes at the funeral of 16-year-old boy, Sharoon

Both Pakistan's prime minister and the powerful army chief have vowed to bring the attackers to justice.

Reports say the military is preparing to launch a new crackdown in Punjab, Pakistan's most populous and wealthiest province - and the heartland of PM Nawaz Sharif's support.

Jamaat-ul-Ahrar's spokesman mocked Mr Sharif on Tuesday, saying that war had "reached his doorstep".

Pakistan's Christians

Christians and Hindus make up the largest minority groups, each representing about 1.6% of the population

Large population in Karachi but also in the Punjab heartland and the cities of Lahore and Faisalabad, and Khyber Pakhtunkhwa province particularly in Peshawar city

Majority are descendants of low-caste Hindus who converted under the British Raj

Most remain poor menial workers, though there are wealthier Christians who came from Goa and are mainly in Karachi

Attacks, including church and hospital bomb blasts and mob attacks on Christian villages, have increased in recent years; the deadliest involved two bombs at a Peshawar church in 2013 which left around 80 dead

Read more: Who are Pakistan's Christians?