The families of the victims of a massive suicide bombing buried their dead on Monday, as the death toll from the attack continued to rise.

The Associated Press news agency cited police putting the death toll at 54. Other sources have said at least 47 people were killed. 

The "Islamic State" militant group claimed reponsibility for the attack in a statement on its Telegram account.

The bombing targeted a Jamiat Ulema Islam (JUI-F) party rally on Sunday led by a pro-Taliban cleric in Pakistan's northwestern Khyber Pakhtunkhwa province that borders Afghanistan.

IS claims responsibility 

Police began recording statements from those in hospital. Feroz Jamal, the provincial information minister, said police were "investigating this attack in all aspects."

The local chapter of the "IS" has recently carried out attacks against the party.

"IS" has accused JUI-F of hypocrisy for being an Islamic political group that has supported secular governments and the military.

The attack comes as Pakistan braces for general elections later this year. The JUI-F party is an ally of the coalition government of Prime Minister Shehbaz Sharif.

"This is a brutality against our political workers," JUI-F senator Kamran Murtaza told DW.

He expected that the attack would impact the election campaigning primarily in Khyber Pakhtunkhwa province.

"The militants aim is to create fear and panic. I think this insecurity will impact the free political participation of politicians," Murtaza said.

EU condemns 'attempt to weaken democracy'

The European Union condemned the blast as "an attempt to weaken democracy" on Monday. A spokeswoman for EU foreign policy chief Josep Borrell said the "terrible attack" sought to "instill terror" in Pakistan.

Afrasiab Khattak, a former Pakistani senator and a political analyst, told DW that both the Pakistani Taliban (Tehreek-e-Taliban Pakistan, TTP) and the "Islamic State's" local branch, "Islamic State Khorasan (IS-K)," contribute to violence and instability in northwestern Pakistan.

The collapse of a ceasefire agreement between the Pakistani government and the TTP last year prompted a resurgence of Islamist militant attacks. The TTP, however, distanced itself from Sunday's attack

"There is a history of terror attacks on JUI-F cadres in Bajaur by IS-K," Khattak said. "The current attack may be of the same nature."

rmt/wmr (AFP, AP, Reuters)

Additional reporting by Haroon Janjua in Islamabad