US Saudi hostage ultimatum looms

People in Mr Johnson's hometown are rallying round his family

Saudi authorities are stepping up their search for a US hostage whose captors have threatened to kill him on Friday if their demands are not met.

Paul Johnson, 49, was seized in the Saudi capital, Riyadh, last Saturday.

The group said on Tuesday he would be killed within 72 hours if al-Qaeda members in Saudi jails were not freed.

Mr Johnson's Thai wife, Thanom, pleaded for his release on Arabic TV, as the US and Saudi Arabia insist they will not negotiate with hostage-takers.

Door-to-door

"I want him to come back to me... He didn't do anything wrong," she told the Saudi-owned al-Arabiya satellite channel.

Amid concern over Mr Johnson's fate, the US state department repeated its advice to US citizens to leave after a series of attacks in the kingdom, where three Westerners were killed within a week.

There was credible information that extremists were planning further action against US and Western interests, the department said.

12 June - US national gunned down in al-Malaz district 8 June - American working for a US defence contractor killed in al-Khalij district 6 June - BBC cameraman killed and BBC reporter seriously injured in al-Suwaydi suburb

Several thousand Saudi officers are involved in a citywide search for Mr Johnson, going from door to door in some areas of the capital.

Twenty FBI agents specialising in hostage rescue are working with Saudi officers, a Saudi official told the Associated Press news agency.

A video from a group calling itself the "al-Qaeda Organisation in the Arabian Peninsula" appeared on an Islamist website on Tuesday, apparently showing Mr Johnson blindfolded.

A man identified as Mr Johnson, who works as a helicopter engineer for US defence contractor Lockheed Martin, is heard giving his name.

The video contained a threat to kill him if the Saudi authorities did not free jailed militants, but did not specify exactly when the deadline set for Friday expires.

The group allegedly holding Mr Johnson posted on the website another tape allegedly showing how its members killed another US citizen, Robert Jacob, last week.

Both the Saudi and US governments have said they will do what they can to free Mr Johnson, but have vowed not to cave in to the militants' demands.

A leading Saudi cleric, the preacher of the capital's Imam Sultana Mosque, urged the kidnappers to release their hostage, in an article in the al-Riyadh newspaper on Friday.

They had "trodden the wrong path" and should "come back to the fold of the community of Islam", Sheikh Mohammed bin Saad al-Saeed wrote.

Son's appeal

In Eagleswood, New Jersey, where Mr Johnson grew up, some 100 friends and relatives held a candlelit vigil for him overnight on Thursday.

A similar vigil was held in Brevard County in Florida, where Mr Johnson worked in the early 1980s, while in the family's hometown of Little Egg Harbor, New Jersey, yellow ribbons and support for the Johnsons are on display.

The family has made emotional pleas for Mr Johnson's safe return.

"Father's Day is right here. Bring my father home for Father's Day," his son, also called Paul, urged US and Saudi officials.