Recently, in which among the following African country, a hostage crisis took place at a gas plant, which resulted in killing of several foreigners?

Algeria
In a crisis that began on 16 January 2013, al-Qaeda-linked terrorists under the command of Mokhtar Belmokhtar took over 800 people hostage at the Tigantourine gas facility near In Aménas, Algeria. After four days, the Algerian special forces raided the site, in an effort to free the hostages. At least 39 foreign hostages were killed along with an Algerian security guard, as were 29 militants. A total of 685 Algerian workers and 107 foreigners were freed.[1][8] Three militants were captured. It was one of many attacks in the Maghreb carried out by Islamist groups since 2002.