QUETTA, Pakistan -- The death toll from a powerful earthquake that struck northwest Pakistan rose to at least 349 early Thursday, authorities said.
The Pakistani military said it had rushed almost 1,000 troops to the area and was sending helicopters in the wake of Tuesday's temblor.
Most of the victims were killed when their houses collapsed. At least 550 people were injured.
The magnitude 7.7 quake hit 145 miles southeast of Dalbandin, in the remote province of Balochistan, which is near the Iranian border. It was felt as far away as New Delhi, the Indian capital, some 740 miles away.
Such a quake is considered major, capable of widespread and heavy damage.
The temblor even resulted in a solitary island's rising from the sea just off the coast, officials said.
Balochistan is Pakistan's largest province but also the least populated and most impoverished. Medical facilities are few and far between and often poorly stocked with medicine or qualified personnel. Awaran district has about 300,000 residents spread out over 11,197 sq. miles.
Authorities in Quetta, the capital of Balochistan province, said the temblor shook the city as well as nearby villages and towns.
"It was very severe," one government official said.
The quake also jolted Pakistan's largest city, Karachi, and other parts of the Sindh, Punjab and Khyber Pakhtunkhwa provinces.
NBC News' Alastair Jamieson, BreakingNews.com's David Wyllie, Reuters and the Associated Press contributed to this report.