Yemeni officials say a day of US Drone attacks has killed at least four people in Northern Yemen, the first report of airstrikes in the Saada province.

Officials say the strikes targeted two households in the region in a search for a local al Qaeda commander, Hadi al-Tais, but there was no confirmation that he was among the dead.

Those killed were suggested to be militants by Yemeni officials; however, the US government considers any military-age males in proximity to any known militant to be militants as well -- a strategy critics say has lead to thousands of civilian deaths in Pakistan, Yemen, Somalia, and other countries in the region.

Deadly US drone attacks in the Middle East and Northern Africa have greatly escalated in the past few years, thanks largely in part to a quickly expanding, yet remote, US base in the Horn of Africa, according to military documents obtained by the Washington Post.

The Post's exposé on the previously obscured destination comes as the last part of a three part investigative series, showing the Obama administration's ongoing development of a complex database now known as the “disposition matrix,” a classified “playbook” that maps out US drone strikes and targeted killing missions in North Africa and the Middle East for at least the next decade.

Sunday's drone strike was the fourth this month in Yemen.