A magnitude 7.6 earthquake occurred some 500 kilometers (300 miles) from the Russian Far Eastern city of Petropavlovsk-Kamchatsky, the Kamchatka office of the Geophysical Service of the Russian Academy of Sciences said.
"Earthquake 14:49 (02:49 a.m. GMT), max magnitude 7.6, total of 463 kilometers from Petropavlovsk-Kamchatsky. The data will be specified," it said.
The first tsunami wave struck near the city of Severo-Kurilsk; it wasn't particularly large and so far its height remains unknown, a representative of the Sakhalin Tsunami Centre said.