Iranian President Ebrahim Raeisi has condemned the terrorist attack in northwestern Pakistan which has left 44 people dead.

In a message to Pakistani Prime Minister Shehbaz Sharif on Sunday, President Raeisi expressed his sympathy to the premier and the friendly and brotherly people of Pakistan.

"We believe that such inhumane and criminal actions will result in no outcome but disgraceful to its perpetrators," Raeisi said.

Iranian Foreign Minister Hossein Amir-Abdollahian also strongly condemned the terrorist bomb attack in Pakistan’s tribal area of Bajaur.

The top diplomat condoled with his counterpart, Bilawal Bhutto Zardari, as well as the government and nation of Pakistan and the victims' families.

“Effective fight against terrorism and extremism is a common security concern for both countries,” Amir-Abdollahian said, adding, “Terrorism is the ominous phenomenon of our time.”

The blast targeted the Jamiat Ulema-e-Islam-F (JUI-F) party in Pakistan's Khyber Pakhtunkhwa province when more than 400 members and supporters gathered under a tent in the town of Khar, near the border with Afghanistan, on Sunday. Khar is located in the former tribal area of Bajaur.

No group has claimed responsibility for the attack, but the local chapter of the Daesh terrorist group has recently carried out attacks against JUI-F.

Earlier, Iran's Foreign Ministry Spokesman Nasser Kan'ani said terrorists once again committed another crime in the neighboring and brotherly country of Pakistan.

He extended Iran's sympathy to the Pakistani government and nation as well as the bereaved.

The Iranian spokesman said the Islamic Republic stands by Pakistan in tackling terrorism.

Pakistan has seen a resurgence of attacks by militants since last year when a ceasefire between the Tehreek-e-Taliban Pakistan (TTP) and the government in Islamabad broke down.

The TTP pledges allegiance to Afghanistan's Taliban. The Pakistani government accuses the Taliban government of providing hideouts to the TTP militants near the border.