Yemen’s al Qaeda wing has stepped up operations in the southern flashpoint province of Abyan, its embassy in the United States said, taking advantage of a power vacuum as a rights group accused forces of unlawful killings. US-based group Human Rights Watch said in a statement on Saturday that Yemeni forces may have killed dozens of civilians in unlawful attacks while fighting an Islamist armed group in the southern province of Abyan since May 2011. In recent months, militants have seized two cities in Abyan, including its capital, Zinjibar. Some 54,000 Yemenis have fled Abyan since then, a government official said last week.