The Yemeni Army regained control of two al Qaeda strongholds on Tuesday—a major breakthrough for the U.S.-backed offensive and its biggest victory in more than a year. The two cities, Zinjibar and Jaar, had been held by militants known as Ansar al-Sharia for more than a year, according to Yemeni troops. U.S. officials said that President Abed Rabbo Mansour Hadi, who came to power in February, is more cooperative than former president Ali Abdullah Saleh, to rooting out the al Qaeda militants. Yemen’s Defense Ministry said the Army, backed by local fighters, had entered Jaar early Tuesday morning and recaptured the city after heavy fighting that killed 20 militants, four soldiers, and two civilians. Ali Saeed Obeid, a military spokesman, told Reuters the fall of Jaar is “an astounding defeat for al Qaeda.”