KANDAHAR, Afghanistan - A legislator who was a vocal Taliban critic in Afghanistan's insurgency-plagued south was killed Thursday by a roadside bomb, family and officials said.

Four others died along with Dad Mohammad Khan in the explosion in southern Helmand province, said his cousin, Aktar Mohammad Khan.

In his role as a parliamentarian, Khan served as a prominent voice against the Taliban in a region where their insurgency is strongest. He fled the country during Taliban rule but returned to become Helmand's intelligence chief after the extremist regime fell in 2001, said Shir Mohammad Akhonzada, the former governor of Helmand.

Meanwhile, international and Afghan troops killed two suspected insurgents and detained 22 others in two separate raids in the east, officials said.

The militants died and four were detained when Afghan and U.S.-led coalition troops conducted a raid on an al Qaeda cell in the eastern Nangarhar province, the coalition said in a statement.

The cell was involved in roadside bomb attacks and facilitated suicide bombings. Troops discovered weapons, ammunition and seven kilograms of opium during the raid, the coalition said.

But Khaiber Momand, the district chief of Bati Kot where the raid happened, said those targeted were civilians, and those detained included the director of the district's development department, Haji Khair, and two of his sons.

Momand alleged that during the raid, troops also beat the mayor of Bati Kot, Mohammad Hassan, and his son, Enayat.

Col. Greg Julian, spokesman for U.S. forces in Afghanistan, said there were "solid, multiple sources of intelligence which led us to this location and to these individuals."

Detainees were being questioned and were suspected of association with insurgent activity, Julian said.

It was impossible to independently verify either claim because of the remoteness of the area.