Twenty-eight Palestinians will this week in Belgium present charges of crimes against humanity against Ariel Sharon, making the Israeli prime minister the latest political leader to face universal jurisdiction outside his own country.

The charges relate to the 1982 massacre in the Shatilla and Sabra refugee camps, Beirut, when Israeli-allied Christian militiamen butchered at least 1,000 unarmed Palestinian civilians.

An Israeli commission of enquiry led by Yitzhak Kahan found Mr Sharon "personally responsible" for the massacre. Mr Sharon, the chief driving force of an invasion that had taken Israeli armed forces into Beirut at the cost of 20,000 lives, subsequently resigned his post as defence minister.

"There is an increasing trend towards universal competence in crimes that are especially heinous, shown by the [General Augusto] Pinochet case and then by the International Criminal Tribunals for both Former Yugoslavia and Rwanda," said Chibli Mallat, a Lebanese lawyer advising the Palestinian refugees.

"We have chosen to present the case in Belgium because it has a universal jurisdiction law, passed in 1993 and strengthened in 1999. It is not necessary for the plaintiff or the accused or the crime itself to have been committed in Belgium.

"What is necessary is that the crimes are so great as to be against humanity or are serious breaches of international humanitarian law. We have assembled gruesome evidence from 28 survivors of the Sabra and Shatilla massacres. Armed Palestinian fighters had left the camps after guarantees of safety given by Philip Habib [the US special envoy]."

The complaint against Mr Sharon will be referred to an investigative judge who will decide how to procede. Mr Mallat said it was possible that Mr Sharon could be arrested if he were to visit Belgium, although he would probably have immunity on any official visit.

"The victims are entitled to justice, after 20 years of oblivion," said Mr Mallat. "This is the first time they will have their say in court."

Mr Mallat has also worked as an advisor to Indict, the international campaign to charge Saddam Hussein, Iraq's president, with crimes against humanity.