(CNN) -- Yemen's defense minister survived an apparent assassination attempt Tuesday when a car bomb exploded near a building he was leaving, officials said.
Twelve people were killed in the blast in the center of Yemen's capital, Sanaa, including eight of the minister's guards, Interior Minister Abdulkader Qahtan said.
The blast happened outside the prime minister's office as Defense Minister Maj. Gen. Mohammed Nasser Ahmed was leaving, authorities said.
The attack hit the third vehicle in his motorcade, Qahtan said. It was the second time the minister was targeted, he said.
Three homes close to the prime minister's office and nine vehicles were damaged, and roads leading to the government building were closed.
Motorcyclists who happened to be in the area took seven of the injured to a hospital. Among the injured was Mohammed al-Qubati, a former ambassador for Yemen to Lebanon, Qahtan said.
The prime minister's office was immediately shut down, and senior officials were evacuated from his office building, Qahtan said. Smoke from the attack covered the skies of Sanaa for more than an hour.
No group immediately claimed responsibility for the blast.
The bombing comes one day after Yemeni forces said they killed Said al-Shihri, second in command of al Qaeda in the Arabian Peninsula.
If DNA testing confirms his death, it "would be a deeply significant blow against AQAP," CNN terrorism analyst Paul Cruickshank said.
White House counterterrorism adviser John Brennan in April described AQAP as "very, very dangerous" and "the most active operational franchise" of al Qaeda.
The group was behind the so-called underwear bomb attempt on a U.S.-bound international flight on Christmas Day 2009 and an effort to smuggle bombs in printer cartridges onto U.S.-bound cargo planes in 2010.
Al-Shihri, who was once held by the United States at Guantanamo Bay in Cuba, was killed Monday in an operation in Hadramawt Valley, Saba reported.
The unrest in Yemen began in 2011 as the population became caught up in the Arab Spring uprisings that swept North Africa and the Middle East.
Ali Abdullah Saleh, Yemen's longtime president, stepped down this year after more than a year of clashes between his supporters and opponents.
CNN's Pierre Meilhan and journalist Hakim Almasmari contributed to this report.