SANAA —  Unidentified assailants opened fire on the motorcade of Yemen’s prime minister on Saturday, an aide said, in an apparent assassination attempt that underscored the volatility of the U.S.-allied Arab country.

Basindwa.

Ali al-Sarari, an adviser to Prime Minister Mohammed Salem Basindwa, said no one was hurt in the attack, which happened in the evening in Sanaa, while the premier was returning home from his office.

No one has claimed responsibility for the attack. But Yemen is home to Al Qaeda in the Arabian Peninsula (AQAP), considered one of the most aggressive branches of the global militant organization, which has previously targeted top officials.

“We strongly condemn this brazen assassination attempt and remain committed to supporting Yemen as it pursues meaningful and peaceful reform through its ongoing transition process,” a U.S. State Department official said in Washington.

President Abd-Rabbu Mansour Hadi said last week that the AQAP’s leader had vowed, in an intercepted phone call, to carry out an attack that would “change the face of history,” and that this was what had led to the temporary closure of many U.S. and other Western embassies in the Middle East, Africa and Asia earlier in August.