Yemen’s al-Qaida branch has exploited the chaos in this embattled country to capture three towns near the southern port city of Aden where pro-government forces have been advancing against Shiite rebels in recent weeks, officials said Thursday.

According to witnesses, al-Qaida’s black banners were raised over buildings in the towns of Rabat, al-Lahoum and al-Masaabin. Security officials said the extremist group seized government buildings without a fight and turned them into military bases.

Upon entering al-Lahoum, al-Qaida fighters demolished a building after accusing its owner of being an agent for Yemen’s former President Ali Abdullah Saleh and his allies, the Shiite rebels known as Houthis, the officials also said. They spoke on condition of anonymity under regulations while the witnesses did not want to be identified, fearing reprisals. […]