US drone strike kills 4 AQAP militants in Yemen
Three "armed fighters of al-Qaeda" died when their vehicle was struck on Saturday in the Sawmaa region of al-Bayda province, the anonymous source said.
On Friday, a separate drone strike killed a local military instructor for al-Qaeda in the same province, he added.
The United States, which considers al-Qaeda's Yemen-based franchise, al-Qaeda in the Arabian Peninsula (AQAP), to be its most dangerous, is the only force operating drones over Yemen.
But it only sporadically reports on a long-running bombing campaign against AQAP.
Last week, the Pentagon reported the death of Abd al-Ghani al-Rasas - a senior al-Qaeda leader killed in a drone strike in the southern Baida province.
"This strike removes an AQAP senior leader and facilitator in the area and will disrupt AQAP's terrorism operations in Yemen and the region," he said in a statement.
"This operation is an example of the US government and our allies' commitment to the people and the government of Yemen to detect, deter, disrupt and defeat violent extremists who threaten progress in the region, as well as threaten to conduct terrorist attacks against innocent people in the region and around the world," Cook added.
Al-Qaeda and the Islamic State jihadist group have exploited a power vacuum created by the two-year-old conflict in Yemen between the government and Houthi rebels, especially in the country's south and southeast.
Al-Qaeda has long been the dominant militant force in Yemen, located next to oil-flush Saudi Arabia and key shipping lanes, but experts say IS is seeking to supplant its extremist rival.
US operations against AQAP in Yemen are separate from a Saudi-led coalition campaign against the Houthis, although the United States is providing logistical and other forms of support to the Arab coalition.