Algeria is or was a big gas producer. A large-scale LNG reception plant was commissioned on Canvey Island in 1964, this received LNG from Algeria.
The In Amenas hostage crisis began on 16 January 2013, when al-Qaeda-linked terrorists affiliated with a brigade led by Mokhtar Belmokhtar took expat hostages at the Tigantourine gas facility near In Amenas, Algeria.
Gas plants and distribution of gas is always going to be vulnerable to terror.