Pakistan ? Roadside bombs struck two vehicles in Pakistan’s volatile northwest Sunday, killing a former irrigation minister and three others in one attack and two anti-Taliban tribal elders in the other.

Public officials and private citizens combatting the growing Taliban-led insurgency in Pakistan have been frequent targets in a wave of violence that has killed more than 600 people in the past two-and-a-half months.

A single attack two days ago killed nearly 100 people when a suicide car bomber struck a sports event near a meeting of tribesmen who supervise an anti-Taliban militia near Pakistan’s South Waziristan tribal area.

The Pakistani army invaded South Waziristan in mid-October in an attempt to neutralize the Pakistani Taliban’s main stronghold in the country, but many militants fled the offensive and have been launching attacks elsewhere in the northwest.