Six persons, including a priest, were arrested outside the Philippine Embassy yesterday while protesting continued U.S. military and economic support for the government of Philippine President Ferdinand Marcos.

Calling the recent election there "a mockery of democratic principles," the demonstrators said they were deliberately staging a protest on the embassy property to show support for Filipinos who have threatened to engage in civil disobedience until Marcos resigns.

"How could you have a free and fair election under a dictatorship? He controls everything," said Elsie Castrence, a coordinator of the Washington Forum on the Philippines, which organized the protest at the embassy, located at 1617 Massachusetts Ave. NW.

Castrence criticized President Reagan's initial description of the election as proving the country has a strong two-party system. Though the president has backed off that statement in recent days, she said the U.S. attempt to get Marcos to share power with oppositon leader Corazon Aquino "is robbing us of our future."

Protesters complained yesterday that the Reagan administration was more concerned about U.S. military bases in the Philippines than the 54 million people who live there. They also expressed concern that once the international spotlight is off the Philippines, Marcos will retaliate against those who campaigned against him.

Arrested yesterday were Gerald Wickenhauser, a priest with the Maryknoll Missions here; Dr. Roberto Castrence; Chip Fay; Dee Ann Malicsi-Dixon; Jim Nelson, and Bill Christeson. All were charged with demonstrating within 500 feet of the embassy, a misdemeanor.