"One Frontier Corps official was also injured in the exchange of fire when the security forces intercepted a convoy of LEJ militants going towards Mastung," a senior police official said yesterday.
The four killed late last night included a top commander of the LEJ, which has been involved in sectarian killings of Shia Muslims and attacks on government and security officials, he said.
"The militants opened fire at security personnel and four of them were killed on the spot," the police official said.
Late last month Punjab Police killed the head of the dreaded LEJ, Malik Ishaq, along with his two sons Usman and Haq Nawaz, and 11 others near Muzaffargarh in southern Punjab.
Ishaq, his sons and accomplices were killed while trying to escape police custody, while six policemen were also injured in that heavy exchange of firing.
Ishaq was on a US list of global "terrorists" and the group he founded has claimed responsibility for the deaths of hundreds of civilians, most of them minority Shia Muslims.