The first Muslim prayer service ever hosted at Washington's National Cathedral, a landmark Christian church in the US capital, was interrupted on Friday by a lone anti-Islamic protester and drew criticism from leading conservative spokesman Rev Franklin Graham.

Admission to the service was by invitation only and security was tight. It was designed to highlight the need for religious tolerance and for people of faith to reach out beyond their religious boundaries.

The protester, a woman from Michigan who declined to give her name, shouted "leave our churches alone" and "Why can't you worship in your mosque?" "Jesus Christ is on that cross over there," she yelled. "Get out of our church. Leave our church alone."

She was removed from the service by a minister and by cathedral police. After the service, outside the church, the protester said she was not arrested, and was not harmed in the altercation. She did not explain why she disrupted the service.

"I didn't do it for myself," she said. "I did it for the Lord."

Graham, son of evangelist Dr Billy Graham and one of America's foremost Christian leaders, warned of the danger of obscuring the uniqueness of Christ when he wrote on his Facebook page: "It's sad to see a church open its doors to the worship of anything other than the One True God of the Bible who sent His Son, the Lord Jesus Christ, to earth to save us from our sins. Jesus was clear when He said, 'I am the way the truth and the life. No one comes to the Father except through Me' (John 14:6)."

In an address during the service, Ebrahim Rasool, the South African ambassador to the United States, who is Muslim, gave a sermon that preached religious freedom and condemned Muslim extremists as a dangerous threat to the world.

"They invade lands, behead journalists, execute civilians and declare war on anyone different to them," he said.

Rasool and the National Cathedral's Rev Canon Gina Campbell organised the service, with help from the All Dulles Area Muslim Society, Council on American-Islamic Relations, Islamic Society of North America, Muslim Public Affairs Council and The Nation's Mosque.

Campbell welcomed the religious gathering, saying the Washington National Cathedral was "a place of prayer for all people".

"Let us stretch our hearts and let us seek to deepen mercy for we worship the same God," she said.

(Additional reporting by Reuters)