Washington indicted on Thursdayd13 Saudi militants and a Lebanese man for the 25 June 1996 bombing and said unidentified "elements of the Iranian government inspired, supported and supervised members of Saudi Hizbollah, engaged in preparing the attack", Attorney General John Ashcroft said in announcing the charges.

Though the indictment did not name or charge any member of the Iranian government, but U.S. investigators had identified a certain Ahmad Sharifi, believed to be a senior Iranian member of the Revolutionary Guards, as one of the suspects responsible for the blast at the military complex near the oil port of Dhahran, CBS had reported, quoting unidentified Federal investigators.

For his part, Saudi Defence Minister Prince Sultan bin Abdalaziz said investigating the explosion is a matter that regards the Kingdom’s Judiciary and no foreign countries, being it the United States. "Only Saudi Arabia has the right to take procedures", he stated.

Appearing annoyed by the U.S. step, the Prince said "Every country has the right to hold discussions with anyone present in that country, but it doesn't have the right to take any procedures," He said in an apparent reference to the indictments.

Saudi Arabia, the top American ally in the Gulf, has feared that U.S. attempts to implicate Tehran in the bombing could drag it into conflict with Iran just as the two countries' relations are beginning to improve.

Speaking to reporters in San’a, the Capital of neighbouring Yemen, the Minister reminded that his country had never named Iran, nor any other nation of involvement in the truck bombing of Khobar.

The United States cut ties with the newly installed Islamic Republic and subsequently froze all Iranian assets in American banks after Iranian students stormed the American Embassy in Tehran on November 1979 and kept some fifty US diplomats as hostages for 444 days.

"It (the indictment) warns the Iranian regime that if it continue to support terrorist organisations and do not behave, the US could name Iranian individual as having participated in the operation and even go further, opt for military action, if the government of Iran is found involved", Mr. Farhang said.

"Until few months ago, opponents to lifting sanctions had few support in the Congress, some senators had even voiced their backing for the removal of the measures, but after that conference and Ayatollah Khamenehe'i’s speech, the atmosphere changed dramatically" he told IPS in a telephone interview.

The indictment explains that the terrorist activities leading to the 1996 Khobar blast began as early as 1993, when members of Hezbollah began extensive surveillance to find American targets in Saudi Arabia.

In 1995, according to the indictment, the terrorists focused on Khobar Towers, which housed U.S. Air Force personnel, assigned to the Persian Gulf region.

"After amassing large amounts of plastic explosives, the terrorists, assisted by and as yet, an unidentified member of the Iranian-assisted and supported Lebanese Hezbollah, referred to in the indictment as John Doe, these terrorists converted a tanker truck into a huge bomb. They denoted that bomb near the north face of the building number 131 at Khobar Towers shortly before 10 p.m. on June 25, 1996", Mr. Ashcroft told a press conference.

Immediately after the bombing, the leaders of the conspiracy fled Saudi Arabia by using fake passports, FBI Director Louis Freeh told the news conference, adding that those charged in the indictments "are not all in custody".

Though he declined to say how many were in the US or Saudi custody, but some official said there are at least two.

President George W. Bush said the Justice Department's investigation into "this deplorable act of terrorism" would continue with additional charges possible.

"And I want to thank the Kingdom of Saudi Arabia for their assistance in this investigation," he said in a written statement released at the White House. Bush also expressed his thanks in a telephone call to Saudi Crown Prince Abdullah.

However, American sources observed that the Kingdom had become less co-operative after the election of Hojjatoleslam Mohammad Khatami as Iran’s President in 1997, the same year when the Islamic Republic became the Head of the Jeddah-based Organisation of Islamic Conference.

In January, Saudi Interior Minister Prince Nayef Bin Abdalazizhad stated that "a handful'' of Saudi nationals had been detained for links to the bombing but that the main suspects were still at large.

"There will come a day not far away when we will say who is behind Khobar'' Nayef had told a Saudi newspaper, assuring that "so far, no foreign country was involved".

The charges in the federal grand jury's 46-count indictment included conspiracy to use weapons of mass destruction, bombing resulting in death and murder of federal employees and could result in the death penalty for some of the accused men and a maximum sentence of life in prison for others

One of those charged was Hani al-Sayegh, a Saudi national who was handed back to Saudi officials by the United States in 1999. He played a far larger role in the attack than initially believed when he was returned to Saudi Arabia, officials said.

Sayegh was detained in the United States for two years before being expelled in 1999 to face charges in Saudi Arabia.

According to the indictment, Hani Sayegh was the driver of a car that signaled "all was clear by blinking its lights" to the bomb truck, which then pulled into position for detonation near the Khobar Towers.

Sayegh was arrested in Canada in March 1997 and met with U.S. investigators at his request in May of that year, according to the indictment. After agreeing to help U.S. authorities, he was moved to a facility in Atlanta, but he then became uncooperative.

The indictment coincides with a resurgence of concern about possible terrorist attacks against U.S. military and civilian facilities in the Middle East. An FBI team investigating the bombing of the USS Cole in Aden harbor was pulled out of Yemen last week because of evidence of an impending attack.

The motivation for the Saudi Hezbollah to allegedly bomb Khobar Towers would be to embarrass the Saudi royal family and show offence that the presence of "pagan" U.S. troops in Saudi Arabia, the sacred land of Islam, presents, terrorism experts said.

The United States and the United Kingdom flies patrols of the no-fly zone in southern Iraq from a base in Saudi Arabia.

The group recruits young men during religious pilgrimages to the Sayyeda Zeinab shrine in Damascus and then transports them to Lebanon for indoctrination, the indictment said.

The underground Saudi group formed in the early 1990s over issues of repression, Ken Katzman, senior Gulf analyst at the Congressional Research Service, said. "That's when we started seeing Saudi Hizbollah get very active," he said.

Before the indictments were announced, sources close to the investigation told CNN that U.S. law enforcement might not have enough evidence to indict Iranian intelligence agents; though U.S. officials have said for months they are suspected of helping to plan the attack.