Riyadh (AsiaNews/agencies) – Killing the American hostage would be a violation of the principles of Islam. Paul Johnson, who was kidnapped last week, has found a supporter among his colleagues. The man said that Johnson is under his personal protection, and therefore – according to Islam teachings - his life must be spared. Terrorists threatened to kill the hostage if Saudi authorities will not release before tonight some al-Qaida prisoners. The government refused to compromise and increased the efforts to rescue the American man. Helicopters are employed in the research. Thanom, Johnson's wife from Thailand, has appealed to the terrorists for the release of her husband. Johnson's colleague, who calls himself "Al Mumin" (the believer), sent an email to many Islamic websites, including the fundamentalist ones. He hopes he can contact the kidnappers. In his email, Al Mumin quotes the prophet Mohammed. "If protection is bestowed on them, it is forbidden to kill them, rob them, injure them". The "Believer" warns the terrorists: "I declare and swear that he is under my protection. If you harm him I will never forgive you; I will always curse you in all my prayers". The letter is a challenge against the fundamentalists. The challenge is grounded on religious principles. A few days ago 6 ulemas denounced the kidnapping of foreign people as a "serious sin". In his letter, Al Mumin affirms that Johnson has always been against American policy and that he is interested in converting to Islam. Al Mumin reveals that he has often invited the American man for dinner, and that he has given him many prayer books and translations from the Koran. The 49-year old American has worked in Saudi Arabia for more than 10 years. He works for Lockheed Martin in Riyadh. Terrorists accuse him of "overseeing the development of the American Apache helicopter that attacks Muslims in Palestine and Afghanistan". The abductors call themselves "al-Qaida in the Arabian Peninsula". Some supporters of the terrorists sent emails where they accuse Al Mumin of being a CIA agent and a servant of the Saudi regime. They also ask the terrorists to execute Johnson. Al Mumin firmly denied he works for the American intelligence agency. "As for those who said I am a servant of the regime, I say that even if what you say is true, didn't the clerics approve of the slaves' right to bestow protection?". He concludes addressing the terrorists: "O Paul Johnson's kidnappers, I am waiting for your response. What will you do?".