(CNN) — An earthquake in Pakistan, powerful enough to prompt the appearance of a small island off the coast, has killed more than 250 people, Pakistani officials said.
The 7.7-magnitude quake struck in a remote, sparsely populated area of southwestern Pakistan on Tuesday, but it had severe consequences.
At least 264 people were killed in Balochistan province, Asad Gilani, the provincial home secretary, said Wednesday.
In addition to the fatalities, about 400 people have been injured, according to authorities. And more people are still feared to be trapped in wreckage. Images from the scene showed some buildings reduced to rubble.
Rescue efforts are under way in the heavily hit districts of Awaran and Kech in Balochistan. But severely damaged communications networks are hindering the operation, said Jan Muhammad Buledi, a spokesman for the provincial government.
Thousands of survivors from the earthquake are facing difficulties in the two districts, he added, saying that authorities have received offers of support from Iran and Turkey.
The Pakistani military has deployed more than 1,000 troops to the affected area to help with rescue and relief efforts, some of them traveling in helicopters and others in convoy on mountain roads.
The troops are entering a difficult region. Militants fighting for a separate state in Balochistan operate out of part of Awaran district, which has been the site of bombings in the past.
The remoteness of the area means that some of the injured are having to be airlifted to major cities like Quetta, the capital of Balochistan, and Karachi, the capital of neighboring Sindh province.
The quake was strong enough to cause a mass 20 to 30 feet high to emerge from the Arabian Sea like a small mountain island off the coast of Gwadar, local police official Mozzam Jah said. A large number of people gathered to view the newly formed island, he said.
Large quakes can cause significant deformation to the earth's crust, particularly visible along coastlines.
The island is about 100 feet in diameter and about one mile off the coast, GEO TV reported.
Zahid Rafi, principal seismologist for the National Seismic Monitoring Center, confirmed the island had formed. He said it was "not surprising," considering the magnitude of the earthquake.
But John Bellini, a geophysicist with the U.S. Geological Survey, said that generally it would be unlikely for such a large island to emerge from a quake like Tuesday's.
Many things, such as the tide, could come into play regarding the rise of the island, he said.
With a depth of about nine miles (about 15 kilometers), the quake struck 43 miles (69 kilometers) northeast of Awaran and 71 miles (114 kilometers) northwest of Bela, the U.S. Geological Survey said.
The tremors lasted two minutes. People flocked out onto the streets of Quetta.
Aftershocks could be felt in Karachi, hundreds of miles to the southeast.