Islamist militants execute three men in south Yemen ADEN (Reuters) - Islamist militants in southern Yemen said they had executed three men on Sunday for giving the United States information used to carry out drone strikes in the area. Residents of the towns of Jaar and Azzan said two Saudis and one Yemeni were beheaded at dawn by militant group Ansar al-Sharia (Partisans of Islamic Law). A spokesman for the group later said none of those executed were Saudi citizens, but all three had been working for the intelligence services of the kingdom, a close U.S. ally. Weakened by months of protests against outgoing President Ali Abdullah Saleh, Yemen's government has lost control of whole chunks of the country, giving Islamist militants room to tighten their grip in the south, notably in Abyan province. A number of key figures in al Qaeda's Yemen-based wing (AQAP) are Saudi militants wanted by the authorities in Riyadh. The United States, a prime target of al Qaeda which tried to blow up an airliner over Detroit in 2009, has been launching drone strikes against militants in the south. Last month, at least 12 people were killed in one such attack. U.S. federal prosecutors said on Friday that Anwar al-Awlaki, a leader of al Qaeda's Yemen affiliate who died in another drone strike last year, had personally directed and approved the attempted airliner attack in which a Nigerian failed to fully detonate a bomb hidden in his underpants. Reporting by Mohammed Mukhashaf; Writing by Isabel Coles; Editing by Alistair Lyon