Cairo - Prominent Islamist lawyers alleged Wednesday that Egyptian security forces conducted a campaign of mass arrests in the wake of a bombing that struck a popular tourist area in Cairo in February.

Mamdouh Ismail, a former member of the armed Islamist group Islamic Jihad and now a defence attorney specialising in terrorism-related cases, on Wednesday told the German Press Agency dpa that "at least 100 Salafists,"
(ultra-conservative Muslim activists), had been detained in recent weeks, and that almost all of them had been released without charge.

"But," he added, "These roundups occur all the time."

On February 23 one person was killed and 20 wounded when a makeshift explosive device was detonated at a tourist cafe in the Khan al-Khalili area of Cairo.

A source in the Egyptian Interior Ministry, speaking to dpa on condition of anonymity because he was not authorized to speak to the media, on Wednesday unequivocally denied there had been a mass-arrest campaign related to the February bombing.

He said investigators had identified the bombers by combing through the list of guests who had stayed at the Hussein Hotel, metres away from the site of the blast, and that they would announce the results of their investigation soon.

Human rights groups have repeatedly accused Egyptian security forces of conducting mass arbitrary arrests in campaigns against Islamist militants.

Months after a car-bomb killed 31 people at the Sinai resort town of Taba in October 2004, the New York-based pressure group Human Rights Watch accused Egyptian security forces of detaining as many as 2,400 people and subjecting many of them to torture.

Montasser al-Zayat, a former associate of al-Qaeda deputy Ayman al-Zawahiri and a former member of the Gamaa al-Islamiya, another armed Islamist organization whose imprisoned leaders renounced violence in 2003, said the number of those detained in connection with the February blast was likely far higher.

Al-Zayat said that the security forces had "arrested more than 4,000 people, most of whom were quickly released without charge."

Dia Rashwan, an expert on Islamist movements at Cairo's government-funded al-Ahram Centre for Strategic and Political Studies, told dpa on Wednesday that the reason that no suspects had been charged with carrying out the attack was that it had likely been perpetrated by individuals without ties to any organized group.

"There is no pressure on the Interior Ministry to produce suspects quickly," he added.

"Security has not finished its investigations into the case. It's better to have a prolonged and accurate investigation than a rushed investigation that falsely accuses someone," he said.

"If it had been one of the (Islamist) groups, it would have been easier (to identify suspects)," he said. "But as it appears to have been an independent attack, the investigation is more difficult." (dpa)