Yemen's former interior minister helped the alleged mastermind of the attack on the USS Cole (searchto pass through security checkpoints in the months leading up to the 2000 bombing, according to a document read out in court Wednesday by a lawyer for five of the accused plotters.

Defense lawyer Abdul Aziz al-Samawi read out an official letter by former Interior Minister Hussein Arab (search), who was removed in April 2001, instructing security authorities to give "safe passage to Sheik Mohammed Omar al-Harazi (searchwith three bodyguards without being searched or intercepted. All security forces are instructed to cooperate with him and facilitate his missions."

The order was valid from April 2000 until the end of 2000. The Cole was attacked on October 12.

The letter alleging a government role in facilitating terror activities appeared to shock prosecutors in court, and even security guards exchanged bewildered looks. Officials at the ministries of interior and foreign affairs refused to comment on the document.

Yemen tolerated Muslim extremists for many years, but after the Sept. 11 attacks its government cracked down on militant groups and aligned itself with the U.S.-led war on terror. It has received U.S. military aid, such as anti-terror training for its soldiers.

Al-Harazi is one of the names used by Abd al-Rahim al-Nashiri, the sixth defendant and the alleged mastermind of the suicide attack that killed 17 American sailors on the Virginia-based ship. Al-Nashiri is being tried in absentia. He is in U.S. custody at an undisclosed location.

The court accepted the letter as evidence, while the prosecutor, Saeed al-Aqel, crumpled a copy of it and threw it on the ground in disgust. It was not immediately clear how the defense obtained a copy of the letter.

The disclosure in the Cole case came on the same day security officials announced the arrest of a suspected Al Qaeda member in Yemen and authorities increased security following foreign intelligence reports warning of a possible attack.

Yousef al-Harazi, a Yemeni, was arrested in a San`a apartment last week during a raid by an anti-terror squad, the officials said on condition of anonymity. They said al-Harazi, who is in his 30s, was among eight militants wanted by authorities.

Other officials said security forces, including the Yemeni coast guard, were instructed to go on a high state of alert and increase their patrols in the Red Sea and the Gulf of Aden this week to prevent any infiltration by terrorist elements. Those security officials, also speaking on condition of anonymity, said the latest instructions included beefing up security at vital oil installations in the country.

The heightened alert came after authorities received foreign intelligence that an Al Qaeda cell was planning to carry out a terror attack in Yemen, they said, adding that possible targets were oil export facilities in the Red Sea.

Observers saw the latest revelation in the Cole case as evidence terrorists had received help from some elements within Yemen's security forces.

"This document confirms that there is a breach in the Yemeni security system. This system has been infiltrated for a long time by terrorist elements, because of old relations," said political analyst Mohammed al-Sabri.

Another analyst, Jamal Amer, said al-Nashiri's possession of such a letter "proves that there is a link between security authorities and these groups."

In the attack, two suicide bombers rammed an explosives-laden boat into the Cole as it refueled in the southern Yemeni port city of Aden. The attack was blamed on Usama bin Laden's Al Qaeda terrorist network.

The six defendants are charged with belonging to Al Qaeda, forming an armed gang with the purpose of carrying out crimes against the state, resisting authorities and forging documents.

If convicted, the men could face the death penalty. However, that sentence is considered unlikely because the defendants are not accused of being the actual bombers.

The Cole trial resumes Sept. 1.