7.4-magnitude earthquake strikes off Russia's Kamchatka Peninsula at 2:00 PM local time Saturday
Tsunami warning issued for Russian coasts within 300km; later downgraded as threat passes.
Epicenter located 111km east of Petropavlovsk-Kamchatsky at a depth of 39.5km.
Largest aftershock of July's devastating 8.8-magnitude earthquake that triggered Pacific-wide alerts