Vietnam state media say a Vietnamese-American pro-democracy activist has been arrested and accused of terrorism for planning a protest to disrupt the April 30 celebrations commemorating the end of the Vietnam War.

State media said Sunday Nguyen Quoc Quan was arrested April 17 after arriving at the airport in Ho Chi Minh City.

Quan, who has a doctorate degree in mathematics and lives in California, is a member of the U.S.-based Viet Tan Party, which is banned in Vietnam. The Viet Tan website describes its organization as “committed to peaceful, non-violent struggle” for the “democratic transition of Vietnam.”

Viet Tan says the Vietnamese communist government's accusations of terrorism against Quan are “completely fabricated.”

Quan was previously detained in Vietnam in 2007 and held for six months for distributing materials promoting non-violent tactics for civil resistance. He was deported in 2008.