According to Express 24/7 correspondent Muhammad Kazim, unknown assailants launched a grenade on a check post there whre these two personnel were posted at the time.
The injured were shifted to CMH for treatment while police and FC personnel had reached the attack site and cordoned off the area.
According to authorities , the personnel have received serious injuries but their condition is stable and were out of danger.
No group has claimed responsibility for the attack, yet.
Security personnel in in Quetta have been under constant attacks in recent times, carried out by militants and local liberation groups.
Earlier three policemen lost their lives when unidentified attackers on a motorbike opened indiscriminate fire on them in Quetta City on Wednesday.
Police sources said the three Balochistan Constabulary personnel were deployed at a check post in Kili Kabir area when the incident occurred.
The deceased were identified as Murad Ali, Sher Ali and Muhammad Nadeem. The bodies had been shifted to Civil Hospital, Quetta.
Area police had registered the case and have begun their investigation with 22 suspects arrested during a search operation in different areas of the city.
(Read: Balochistan violence claims lives of 3 more policemen)
Earlier, last week, paramilitary troops, police and the Anti-Terrorism Force (ATF), on Monday arrested around 150 suspects during a house-to-house search in connection with the targeted killings of SHO Manzoor Tareen and two constables.
(Read: House-to-house search in Quetta: 150 held after policemen’s killings)