The tribunal said in a statement that two investigators with their female interpreter went to a pre-arranged meeting accompanied by judicial police and the army when a group of people showed up unexpectedly and attacked the investigators.

“The attack this morning in Beirut against staff members of the Special Tribunal for Lebanon is a deplorable attempt to obstruct justice,” the tribunal said in a separate statement.

“Those who carried out this attack must know that violence will not deter the Special Tribunal for Lebanon, a court of law, from fulfilling its mandate.”

Tension has escalated in Lebanon over the tribunal in the past few months and the country almost sank into a new turmoil after reports that the court will indict members of the Shiite militant group Hezbollah.

“The Lebanese army extracted the three staff members and brought them back safely to the STL Beirut Office where they were provided with medical attention,” the tribunal said.

The tribunal’s chief will report the incident to the Lebanese government and the UN secretary-general.

Hezbollah, part of Lebanon’s national unity government, has denounced the UN-backed court as a tool of US and Israeli policy and called on Prime Minister Saad Al-Hariri, Rafik’s son, to repudiate the tribunal. (Editing by Elizabeth Fullerton)