Dr Muhammad al-Massari, a political activist living in exile in London, has told Aljazeera.net that resistance attacks in Iraq will continue to escalate in Baghdad.
''There are around 5000 mujahidin fighters from Saudi Arabia in Baghdad, and many others joining them from all over the Muslim and Arab world.
"These men have already stepped up their efforts to kick out the American imperialists from Iraq, but what we are seeing is the tip of the iceberg,'' he said.
Al-Massari claims that the resistance attacks against the American fighters will spread to Saudi Arabia where anti-western and Saudi government sentiment is rising.
Calm before the storm
''For the past 10 years, Saudi Arabia has been relatively calm, the mujahidin were busy recruiting and training men from as far afield as Chechnya and Kashmir to fight against American aggression in the Muslim world."
Al-Massari claims that 10 years ago it would have been inconceivable for Muslim fighters to take arms and launch attacks within a Muslim country.
However, with Muslim countries such as Saudi Arabia and Kuwait allowing American troops to be stationed in their countries, resentment against Arab regimes has increased.
''For the past 10 years Saudi Arabia has been relatively calm, the mujahidin were busy recruiting and training men''
Dr Muhammed al-Massari,
''The resistance fighters had a dilemma in the past when it came to fighting within a Muslim country because of the rules of Sharia (Islamic) law.
"However, as we are seeing in Saudi Arabia itself Muslims are prepared to launch attacks within their own countries''.
Both the Qatar and London embassies of the Saudi kingdom declined to comment on al-Massari's allegations.
Al-Massari's remarks coincide with the American government issuing warnings that an attack against western interests in the kingdom is imminent.
The warning, which the Americans describe as ''credible'' comes at a time when there is huge discontent among the Saudi population against their rulers, the royal family.
Americans have been warned to avoid non-essential travel to the kingdom, and advised citizens to be vigilant in the Gulf region.
The Bush administration called on Syria and Iran on Tuesday to take action to stop cross-border infiltration by guerrillas into Iraq.
US military officials say there are signs that foreign fighters were behind the four suicide bombings that killed 34 people and wounded 230 on Monday in Baghdad's bloodiest day since Saddam Hussein was overthrown.
The US administrator in Iraq, Paul Bremer, said over the weekend that most of the "terrorists" in Iraq were not Iraqis but came from countries such as Syria, Saudi Arabia, Yemen and Sudan.
Border control was a major issue in Iraq, he said, adding that it was very difficult to seal the country's borders.
According to al-Massari, the Saudi royal family are also targets for the mujahidin fighters who are angry at the Saudi government for ''inviting the Americans on to their holy soil''.
Al-Massari plans to launch a political party in London, calling for reforms in Saudi Arabia.
His group, the Committee for the Defence of Legitimate Rights, is keeping a close watch on events unfolding in the region.