The death toll from a suicide bombing at a famous shrine in Pakistan has climbed to 75, with another 200 people wounded.

Fazal Palejo, a senior health official in Sindh province, provided the death toll. Three security officials confirmed the toll, saying the dead included 20 women and nine children.

The security officials spoke on condition of anonymity because they were not authorized to brief reporters.

The Islamic State in Iraq and Syria claimed responsibility for the attack on their Aamaq news agency, saying a suicide bomber had targeted a "Shia gathering" at the shrine.

Pakistani officials said the suicide bomber walked through a gold plated door and entered the main hall of the shrine of Lal Shahbaz Qalandar before setting off his payload amid a gathering of worshippers.

Pakistani hospital staff make arrangements outside an emergency ward for the victims of a suicide bombing at a famous shrine in interior Sind province, in Karachi, Pakistan. (Shakil Adil/Associated Press)

Senior police officer Rashad Hayat said the attacker detonated his suicide jacket when hundreds of worshippers were performing their weekly mystical dance — called Dhamal — at the shrine in the town of Sehwan in the southern Sindh province.

Local government official Munawar Ali also confirmed that attack and said their priority was to quickly transport the victims of the suicide attack.

The military says it is dispatching troops to contribute to the relief effort.