SANAA, Yemen — Two U.S. drone strikes killed a total of nine suspected al-Qaida militants today, a Yemeni military official said, the sixth and seventh such attacks in less than two weeks as the Arab nation is on high alert against terrorism.

The uptick in drone strikes signals that the Obama administration is stepping up its efforts to target Yemen’s al-Qaida offshoot — al-Qaida in the Arabian Peninsula — amid fears of attacks after the interception of a message between its leader and the global leader of the terror network.

Since July 27, drone attacks have killed 31 suspected militants, according to an Associated Press count of the dead provided by Yemeni security officials.