The local economy consists mostly of smuggling fuel from Iran or harvesting dates.
The area where the quake struck is at the center of an insurgency that Baluch separatists have been waging against the Pakistani government for years. The separatists regularly attack Pakistani troops and symbols of the state, such as infrastructure projects.
It's also prone to earthquakes. A magnitude 7.8 quake centered just across the border in Iran killed at least 35 people in Pakistan last April.
Tuesday's shaking was so violent it drove up mud and earth from the seafloor to create an island off the Pakistani coast.
A Pakistani Navy team reached the island by midday Wednesday. Navy geologist Mohammed Danish told the country's Geo Television that the mass was a little wider than a tennis court and slightly shorter than a football field.
The director of the National Seismic Monitoring Center confirmed that the mass was created by the quake and said scientists were trying to determine how it happened. Zahid Rafi said such masses are sometimes created by the movement of gases locked in the earth that push mud to the surface.
"That big shock beneath the earth causes a lot of disturbance," he said.
He said these types of islands can remain for a long time or eventually subside back into the ocean, depending on their makeup.
He warned residents not to visit the island because it was emitting dangerous gases.
But dozens of people went anyway, including the deputy commissioner of Gwadar district, Tufail Baloch.
Water bubbled along the edges of the island. The land was stable but the air smelled of gas that caught fire when people lit cigarettes, Baloch said.
Dead fish floated on the water's surface while residents visited the island and took stones as souvenirs, he added.
Similar land masses appeared off Pakistan's coast following quakes in 1999 and 2010, said Muhammed Arshad, a hydrographer with the navy. They eventually disappeared into the sea during the rainy season.
Santana reported from Islamabad. Associated Press writers Abdul Sattar in Quetta, Asif Shahzad in Islamabad and Adil Jawad in Karachi contributed to this report.
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