Members of a Seattle film crew detained in Nigeria over the weekend on suspicion of traveling in a restricted area have been released, a senator from Washington said Wednesday.

The five crew members will have to complete final processing by Nigerian authorities on Friday, said U.S. Sen. Maria Cantwell.

The Americans and their Nigerian companion were picked up by U.S. Embassy representatives at a detention center and taken to Abuja, said Leslye Wood, spokeswoman for "Sweet Crude," the documentary the crew was filming about oil production in the Niger River Delta.

"Obviously we are so happy and relieved to know that they have indeed been released," Wood said. "We sure will feel better when we can hear their voices for ourselves."

Information on their health and when the filmmakers will return to the United States was not available Wednesday afternoon.

This was their fourth trip to the Niger Delta during the past 2 1/2 years. Wood, who traveled with the group on two of those trips, said the filmmakers had no previous problems.

The crew entered the country legally on April 5 and was transparent in its visa application, making it clear that they would be completing the filming of the documentary.

Various foreigners have been picked up in the Niger Delta in recent months as security forces have stepped up efforts to quell unrest. Several people, including two filmmakers working on a different documentary, were expelled from the country on alleged visa violations.

Sandi Cioffi, 46, director of "Sweet Crude," has produced or directed several films, including "Crocodile Tears," about an HIV-positive man who makes a deal with the devil, and "Terminal 187," a half-hour drama on teen violence.

She also traveled to South Africa to film that country's transition from apartheid in 1995.

Tammi Sims, 35; Cliff Worsham, 39; and Sean Porter, 25, make up the rest of the crew detained in Nigeria. Joel Bisina, a peace mediator and founder of Niger Delta Professionals for Development in Warri, was traveling with them.