An Islamic State suicide bomber has targeted worshippers at a famous shrine in southern Pakistan, killing at least 72 people and wounding more than 50 others, officials said.

The attacker detonated his suicide jacket when hundreds of worshippers were performing their weekly mystical dance - called Dhamal - at the shrine of Lal Shahbaz Qalandar, named after the famous Sufi saint buried there, senior police officer Rashad Hayat said.

Authorities transported at least 30 bodies to hospitals following the deadly attack in the town of Sehwan in the southern Sindh province, according to state-run Pakistan Television. 

IS claimed responsibility for the attack on its Aamaq news agency, saying a suicide bomber had targeted a "Shiite gathering" at the shrine.

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

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