Two senior officers in the Yemeni security forces were killed Sunday in separate attacks, local media reported, dpa reported.
Gunmen shot Major Abdullah Daifullah, head of the rapid response police in central al-Baida province, as he was on his way to work, local news site Al-Masdar Online reported.
In the central city of Taiz, Colonel Saddam Hussein al-Tahiri, head of operations for the city's presidential palace, was shot by unknown gunmen, Al-Masdar Online said.
The site also reported that Yemeni Socialist Party leader Yassin Said Numan escaped an assassination attempt on Saturday when attackers opened fire on his car.
Yemen has seen frequent attacks on senior army and security officers in the last two years.
The government usually blames them on al-Qaeda in the Arabian Peninsula (AQAP), seen as one of the international extremist network's most active and dangerous branches.
The killings come days after gunmen burst into the Defence Ministry headquarters in the capital, Sana'a, exploding a car bomb and gunning down doctors, nurses and patients in a military hospital inside the complex.
The military, in an initial report on Thursday's attack, put the total death toll at 56, with 215 injured.
It said there were thought to be 12 attackers, mostly of Saudi nationality.