Paul M. Johnson Jr. is shown in this undated family photo released by his son Paul Johnson III, in Port St. John, Fla., Thursday, June 17, 2004. Johnson, 49, a Lockheed Martin employee who resided in Brevard County, Fla. was kidnapped in Saudi Arabia on Saturday, June 12, 2004. Al-Arabiya television reported Friday, June 18, 2004, that Johnson Jr. has been beheaded. (AP Photo/Courtesy of Paul Johnson III, File)

RIYADH, Saudi Arabia (AP) - An al-Qaida group said Friday it killed American hostage Paul M. Johnson Jr, posting an Internet message that showed photographs of a beheaded body that appeared to be his.

The statement was posted on a Web site where the group frequently makes announcements. Also posted were three still photos showing a head that appeared to be Johnson's.

The message, in the name of Al-Qaida in the Arabian Peninsula, appeared as a 72-hour deadline set by the group on Tuesday ended.

"In answer to what we promised ... to kill the hostage Paul Marshall (Johnson) after the period is over ... the infidel got his fair treatment," the statement said.

"Let him taste something of what Muslims have long tasted from Apache helicopter fire and missiles," the statement said.

Johnson, who worked on Apache helicopter systems for Lockheed Martin, was kidnapped last weekend by militants who threatened to kill him by Friday if the kingdom did not release its al-Qaida prisoners. The Saudi government rejected the demands.

The photos posted with the statement showed a severed head, placed on the back of a body. The body was wearing an orange jumpsuit and the face was turned toward the camera.

The Enemy - Al-Qaida Leaders

The day Johnson was seized, Islamic militants shot dead Kenneth Scroggs, from Laconia, N.H., in his garage. Scroggs, who also worked for Lockheed Martin, was killed days after another American was slain in an escalating al-Qaida campaign against Westerners in the kingdom.

Johnson was the second American abducted and slain by his kidnappers in the Middle East in just over a month.

Nicholas Berg, a businessman, was beheaded in Iraq, and his last moments later appeared on a videotape posted on an al-Qaida-linked Web site. U.S. officials say al-Qaida-linked Muslim militant Abu Musab al-Zarqawi may have been Berg's killer.

In Washington, spokespersons for the CIA and the State Department said the agency was not able to immediately confirm the report of Johnson's beheading.

A senior Saudi official in Washington, who spoke on condition of anonymity, said the government did not yet have any independent confirmation of Johnson's death. "There is no body, and we know of no videotape," said the official.

As Friday's deadline approached, Saudi security forces launched an all-out search, going door-to-door in some Riyadh neighborhoods, as Johnson's wife went on Al-Arabiya television Friday pleading for his release.