The four succumbed to their injuries in a hospital early on Wednesday in Jaar, 11 kilometres (six miles) north of Zinjibar, the medical source told AFP, adding that two other wounded militants and a civilian were brought in.
The al-Qaeda suspects were hit by army shelling of Zinjibar, Abyan’s provincial capital that has mostly been overran by gunmen since May.
Jaar and Shaqra, in addition to Zinjibar, remain controlled by gumen, while advancing army troops have seized control of the villages of Dofes, Al-Kud and Al-Matla, on the outskirts of Zinjibar, local sources said.
The army now controls the road linking Zinjibar with the main southern city of Aden — a stretch of 50 kilometres.
According to the supreme security committee, more than 300 al-Qaeda suspects have been killed in Abyan since May. Unofficially, military sources put the army casualty toll at 183 troops dead and more than 250 wounded.
On Tuesday, a military official said Defence Minister Mohammed Nasser Ahmed Ali escaped unharmed when a roadside bomb targeted his convoy in Al-Kud but two guards of the south’s military commander, General Mehdi Maqwala, were killed.
A defence ministry official, however, cited by Saba state news agency, denied the reported explosion.
The lawless southern and eastern provinces of Yemen have provided safe havens for al-Qaeda militants to regroup, especially over the past seven months of mass protests across the country against President Ali Abdullah Saleh.