More than 8,900 Long Island Power Authority customers briefly were without electricity Friday, primarily in Montauk and Amagansett.

LIPA spokesman Mark Gross said a transmission line that went out in East Hampton caused the outages.

The line was tripped at about 11 a.m., affecting less than 10,000 homes and businesses, about 1 percent of LIPA's customers, Gross said.

By 12:20 p.m., all of the affected customers were back on line, Gross said.

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Gross said the cause of the transmission trip was being investigated.

At about 11:30 a.m., said 6,458 customers were without electricity in Montauk and 2,347 in Amagansett.