At least six paramilitary soldiers were killed and 22 were injured in a suicide attack in southwest Pakistan on Tuesday, days after a suicide bombing at a Shi'ite Mosque in northwest Pakistan killed 63 people, officials said.

Militant violence has risen in the South Asian nation amid political instability as country's opposition parties prepare to bring a no-confidence vote against Prime Minister Imran Khan in the coming days.

The Islamic State affiliate in the region known as Islamic State in Khorasan province and headquartered in Afghanistan claimed Tuesday's attack in a statement posted by the SITE Intelligence group.

"The bomber first hurled a grenade which failed, after which he blew himself up close to paramilitary men, killing six," Nasroor Alam Kolachi, a senior police officer of the Sibi District in South-West Balochistan province, told Reuters.

The men were ending security duties after an annual cultural festival attended by President Arif Alivi. He had left the venue before the attack.

On Friday, a suicide bombing at a Shi'ite mosque in the northwestern Pakistani city of Peshawar killed at least 64 people, police and hospital officials said. [L2N2V70NG]

The Peshawar bombing was later claimed by Islamic State.

(Writing by Syed Raza Hassan; Editing by Cynthia Osterman)