Sanaa, Yemen (CNN) -- At least 15 Yemeni troops were killed and more than a dozen injured when suspected al-Qaeda militants attacked a heavily guarded government military base in southern Yemen Friday, security officials said.
The attack started when militants drove a vehicle loaded with explosives into the base in Abyan province, three local security officials said. The vehicle detonated near a crowd of troops.
A gun battle then ensued between militants and troops, culminating in the deaths of all nine militant attackers, security officials said.
The death toll for government forces climbed from initial reports of 12 to 15 after three soldiers died from their injuries. Officials warned the number could still rise further.
The violence comes a day after eight suspected al Qaeda fighters were killed in Abyan province by a U.S. drone strike, according to senior Yemeni security officials. Among those killed was Nader al-Shadadi, a senior leader within Al Qaeda in the Arabian Pensinsula, which has been blamed for numerous attacks in Yemen.
Al Qaeda gained in strength in the country last year after taking control of several towns in south Yemen. The militant group benefited from political unrest that led to Yemen's long-time ruler Ali Abdullah Saleh stepping down from power in exchange for immunity from prosecution.
Upon coming to power in February, President Abdu Rabo Mansour Hadi vowed to fight al Qaeda and refused to halt attacks against its members until they laid down arms and surrendered.
This, however, has not completely weakened al Qaeda, which continues to target government forces in deadly attacks that have killed hundreds of troops and pro-government tribal fighters since May.
It has resorted to suicide attacks and car bombs after losing control of a number of towns in south Yemen, including Shaqra.