The leaders said innocent people had died in the raid that took place earlier this week in tribal-dominated South Waziristan. Eighteen suspects were also captured by the army in the operation.
"The people who have been targeted belong to the Uzbek tribe of Afghanistan and they had no links with al-Qaida or Taliban," Qazi Husayn Ahmed of the Jamaat-i-Islami party said.
"Among the eight dead were Uzbeks and Afghans. They were working as farmers in the area. There are no important al-Qaida members among those arrested," he added.
Liaqat Baloch, the Jamaat's parliamentary party leader, called the raid a "disgrace."
"The government is making such raids in tribal areas to please Americans but it will create serious security problems for the country on the western border," Baloch said.
The criticism of the raid comes a day after Pakistani President, Pervez Musharraf, renewed his resolve not to allow the country to be "used or misused by international extremists."
"There will be no extremists here in Pakistan," Musharraf said.
The army raid in South Waziristan was described initially by the army as its fiercest engagement till date with the al-Qaida.
The army said the raid was on an important al-Qaida hideout.
But officials since then have begun to admit that no senior al-Qaida leaders were among the dead or captured suspects.