Washington: The United States on Wednesday blacklisted a shadowy Al Qaida breakaway faction behind the bloody siege of an Algerian gas plant, and the leader of a Palestinian group fighting for Islamists in Syria.

The Signatories in Blood, an armed unit founded by the one-eyed Mokhtar Belmokhtar last year when he split from Al Qaida in the Islamic Maghreb, was designated a foreign terrorist organisation by the State Department.

The group, also known as the Al Mulathamun Battalion, “claimed responsibility for the January 2013 attack against a gas facility near In Amenas, Algeria,” the department said in a statement, adding that three Americans were among the 38 civilians killed in the siege.

In a separate move, the head of the Palestinian wing of the Syria-based Al Nusra Front, Usamah Amin Al Shihabi, was also blacklisted as a “global terrorist.”

Wednesday’s designations bar US citizens and companies from having any dealings with either the Algerian group or Al Shihabi.