Karachi/Baghdad: Two bombings in Iraq and Pakistan claimed by the Islamic State have killed more than 100 people on Thursday.

A suicide bomber attacked a crowded Sufi shrine in southern Pakistan on Thursday, killing at least 72 people and wounding dozens more in the deadliest of a wave of bombings across the South Asian nation this week.

Pakistan's Prime Minister Nawaz Sharif has condemned the attack. Credit:AP

Meanwhile, a car packed with explosives has blown up in southern Baghdad, killing at least 48 people and wounding 55, security and medical sources say, in the deadliest such attack in Iraq this year.

Islamic State, the Middle East-based militant group which has a small but increasingly prominent presence in Pakistan, claimed responsibility for the attack in that country, the group's affiliated news agency AMAQ reported.