From Middle East Security Report ( published weekly in Scotland)

Further attacks on US targets around the world, like the 7 August bombings of two US embassies in East Africa, are a certainty. Just how soon the next attack will be, however, is not known.

The major security difficulty is that the US authorities have to determine the validity of some 30,000 threats that are allegedly received by potential US targets each year.

Since the bombings in Kenya and Tanzania, the US has shut-down around half a dozen embassies including those in Sudan and Uganda. Embassy stafFf working in outlying buildings in Cairo were relocated in the main compound, and security has been noticeably stepped up in Yemen and Saudi Arabia.

There is a general consensus that Islamist extremists perpetrated the attacks, though some commentators still feel that the West is too quick to blame Muslims. Nevertheless, there are undoubtedly Islamist extremists who wish to cause such devastation.

The location of the bombed embassies made them easier targets than many US embassies around the world. However, their location also made it inevitable there would be casualties among African civilians.

More than 250 people died in the blast in Nairobi, and 10 were killed in Dar Es-Salaam, while some 5,500 others were injured. The majority of the dead were Africans, though 12 Americans died in Nairobi.

The bombers may well have hoped that more American casualties might prompt the US to follow a more isolationist foreign policy. On the other hand, more African casualties might prompt the alienation of the US by the host nation. In the aftermath of the bombings, many local media commentaries condemned the response of US officials as putting Americans first and jeopardising African lives.

The Arab and Islamic world has sought allies in Africa. Israel, too has been keen to boost cooperation with East African countries in a bid to improve facilities for monitoring the potential growth of anti-Israeli Islamist movements in the region. However, while the bomb blasts could provoke some anti-Islamic sectarianism, Israel may have won friends for the well-publicised efforts of the Israeli National Rescue Unit in helping the mainly African victims in Nairobi.

A previously unknown Islamist group calling itself "The Islamic Army for the Liberation of Holy Places" (IALHP) claimed responsibility for the East African bombings, and promised more attacks would follow to drive US and Western forces from Islamic countries in general, and Saudi Arabia in particular.

Some 35,000 Americans, including about 4,500 military personnel, are based in Saudi Arabia - home to Islam's two holiest shrines in Mecca and Medina.

A series of statements sent from the IALHP said the Nairobi bombing was carried out by two men from Mecca, while an Egyptian staged the Dar Es-Salaam attack, However, eye-witness reports suggest more bombers were involved. The statements called for the release of Sheikh Omar Abderrahman,

the Egyptian cleric serving a life sentence in a US prison for plotting bombings in New York, and the release of several other apparently radical Islamist preachers in Saudi Arabia.

While the credibility of the IALHP claim is not clear, Osama Bin Laden, who heads the International Islamic Front for Jihad, remains the main suspect.

The Afghan-based Saudi dissident appears to share the same principles as the IALHP and could easily have sponsored the group's activities.

On 27 May, Bin Laden proclaimed his Islamic Front from his hideout in Khost in Afghanistan He vowed not to rest until Americans and Israelis have been driven from Saudi Arabia and Palestine.

Bin Laden, 42, has built up a network of hundreds of followers, many of whom fought against the Soviets in Afghanistan. He funds their activities with his inherited wealth estimated at US$300 million. He is believed to have formed a loose coalition of half a dozen radical Islamist groups from the Gulf, Egypt, Pakistan and Afghanistan. He also has followers among Islamist extremists based in many other countries, including in the West, and possibly even in Kenya and Tanzania.

The bombings in East Africa are indicative of the increasing transnationalisation of Islamist militant groups. The perpetrators of the attacks are likely to have come together under the direction and sponsorship of someone like Bin Laden solely for the bombings, and would have subsequently disbanded.

The planning for the bombings suggests an advanced level of coordination and the possible involvement of state institutions. Significantly, Bin Laden is reported to have held talks with a senior officer of Iran's Revolutionary Guards Corps in mid-February.

Any cosiness that Bin Laden has with hardline elements among Iran's ruling elite, however, belies the fact that he resides and operates from territory controlled by the Afghan Taleban movement which is vehemently opposed to Iran.

Nevertheless, two Iranian diplomats based in Nairobi, and two in Tanzania, allegedly left East Africa about two weeks before the bombings. The four men reportedly have close ties with Iran's hardline conservatives as well as the Revolutionary Guards. One of the four, Ali Saghaian, the Ambassador in Dar Es-Salaam, was accused by an Argentinian judge of helping to organise the 1994 bombing of the Jewish community centre in Argentina where he was a diplomat. That blast killed 89 people. The Argentinian government believes Tehran played a key role in that blast, as well as the 1992 bombing of the Israeli embassy in Buenos Aires which killed 29 people.

Other speculation has suggested that Baghdad or Khartoum could have a hand in the 7 August attacks, but as international efforts get underway to find those responsible, the chances of a satisfactory investigation are small.

The US has sent some 175 FBI personnel to investigate the East African bombings in cooperation with the US intelligence agencies, the State Department's Diplomatic Security Service and others.

The last major attack on a US facility abroad was the June 1996 car bombing of a military housing complex near Dhahran, Saudi Arabia, which killed 19 Americans. The perpetrators have not been brought to justice, and again it is Bin Laden and hardliners in Tehran who are the main suspects.

Israeli Prime Minister Binyamin Netanyahu has offered the help of Israel's Mossad and other intelligence agencies in tracking down the bombers.

Nairobi has long hosted an important Mossad listening post. Indeed, Israel had recently advised the US to treat with scepticism a warning by an intelligence source that the US Embassy in Nairobi might be the target of a bomb attack, "Ha'aretz" reported on 12 August. David Bar-Ilan, a senior aide to Netanyahu, dismissed the report as baseless.