(New York) - The Yemeni government's acknowledgment that an airstrike killed more than 42 civilians in December 2009 is a stark reminder of the need for careful targeting when using such counterterrorism measures, Human Rights Watch said today.

The deputy prime minister for defense and security, Rashad al-Alimi, apologized on March 3, 2010, to victims' families for the deaths during the airstrike, which was meant to target al Qaeda operatives. The December 17 strike in southern Abyan was widely reported to have been assisted by the US. Al-Alimi described the killings as "mistakes" and offered the families compensation.

"Civilian deaths in counterterrorism operations can have a strikingly counterproductive impact," said Joanne Mariner, terrorism and counterterrorism director at Human Rights Watch. "The US has learned the hard way that such deaths can anger and alienate people who normally would not support groups such as al Qaeda."

The Yemeni authorities had initially said the airstrike killed 34 al Qaeda members. Later, however, officials said 14 al Qaeda members were killed.

With the US government more than doubling counterterrorism assistance to Yemen this year, Human Rights Watch called on leaders in both countries to heed US General Stanley McChrystal's directive from 2009 on the lessons learned from Afghanistan. "We must avoid the trap of winning tactical victories - but suffering strategic defeats - by causing civilian casualties or excessive damage and thus alienating the people," General McChrystal wrote.

The US and Yemeni governments have worked together closely in using airpower against the Yemen-based branch of al Qaeda, known as Al Qaeda in the Arabian Peninsula, particularly in areas outside the central government's authority where ordinary law enforcement operations are difficult. But lack of a ground presence increases the risk of poor intelligence, and of local actors manipulating intelligence for their own purposes, Human Rights Watch said.

Human Rights Watch is particularly concerned about the potential for manipulation because of Yemen's inconsistent approach to confronting al Qaeda in the past and its history of resorting to repressive measures to quell political dissent.

"Many Yemenis fear the Yemeni government more than they fear al Qaeda," Mariner said. "The US and Yemen should take all feasible precautions to ensure that counterterrorism operations do not harm the very people they aim to protect."