France is considering whether to extend its airstrikes to Syria and is increasing security in public places after militants linked to the Islamic State group beheaded a French hostage, officials said Thursday.

President Francois Hollande’s office announced that France will “intensify” its support for Syrian opposition forces fighting the Islamic State extremists. A presidential aide would not elaborate on what kind of support or whether it could involve military action.

Hollande held an emergency defense meeting Thursday, a day after the killing of 55-year-old mountaineering guide Herve Gourdel was announced. […]