The 7.7-magnitude quake struck Tuesday afternoon in the province, toppling thousands of mud-built homes as it spread havoc through Awaran and Kech districts and the southwestern parts of the country.
At least 350 people have been confirmed dead and 619 others wounded, according to Balochistan government spokesperson Mohammad Jan Buledi.
Pakistan's military on Wednesday rushed to reach the scene of the earthquake to launch a relief operation in the affected areas.
"A total of six districts, Awaran, Kech, Gwadar, Panjgur, Chaghi and Khuzdar, and a population of over 300,000 have been affected by the earthquake," Pakistani official said this morning in a press conference.
Abdul Rasheed Baloch, a senior official in the district, said teams had worked through the night to try to retrieve bodies and survivors from the rubble. "Around 90 per cent of houses in the district have been destroyed. Almost all the mud houses have collapsed," he said.
A 7.6 magnitude quake in 2005, centred in Kashmir, had killed at least 73,000 people and left several million homeless in one of the worst natural disasters to hit Pakistan.
Iran's Red Crescent reported no damage from the latest quake over the border from Pakistan.