LONDON, March 28 (JTA) — Lawyers for two Palestinians jailed for their role in the August 1994 bombing of the Israeli Embassy here are scheduled this week to challenge a decision by Britain’s MI5 intelligence agency to suppress two documents that show the agency had prior knowledge of the attack. The disclosure that MI5 knew the attack was imminent was made by former agent David Shayler, who revealed that the warning was passed to an MI5 officer but never acted upon. The officer denied knowledge of the warning, but an internal investigation by the agency turned up the hidden information. When Shayler revealed the existence of the document in November 1997 — one year after the Palestinians, now serving a 20-year sentence, had been placed in prison — British Home Secretary Jack Straw denied that the security services might have prevented the attack, but he conceded that Shayler “could have gained this mistaken impression.” Straw justifies suppressing the document on the grounds of national security. The other document is said to contain the MI5 report on the bombing and to include details of contacts between British and Israeli forensic experts on the explosives used in the attack. At a secret hearing last week, High Court judges agreed that the documents should continue to be withheld from the defense. But defense lawyers are expected to mount a challenge on Monday based on a decision last month by the European Court of Human Rights, which ruled in another case that three men who had been jailed for life for murder were denied a fair trial because police papers were suppressed. The two Palestinians, Jawad Botmeh, 31, and Samar Alami, 33, were convicted of having been part of the team that plotted the bombing, although neither was accused of planting the bomb. Botmer and Alami, both university graduates living in England, admitted that they had conducted experiments using homemade explosives in a remote area of northern England with the intention of sharing the results with Palestinians in the West Bank and Gaza Strip. But they denied that they were involved in the embassy bombing or the bombing a few hours later of a building in north London that housed a number of Zionist organizations. Some 19 people were injured in the attacks, which were claimed by the previously unknown Jaffa Unit of the Palestinian Resistance group, but there were no fatalities. The embassy suffered extensive damage when explosives packed into a car exploded seconds after it was parked alongside the building by a woman. The driver has never been found — nor has another woman, identified as Rida Mughrabi, who has been described as a key defense witness.