BEIJING - A strong earthquake jolted Sea of Okhotsk on Tuesday, and no tsunami alert has been issued and no damage reported so far.

The temblor, which struck at 0259 GMT Tuesday with an epicenter 158 km northeast of the Russian town of Poronaysk and 625.9 km deep, measured 7.7 magnitude, according to the latest update by the US Geological Survey (USGS).

Meanwhile, the Japan Meteorological Agency placed the magnitude at 7.3, while the China Earthquake Network Center put it at 7.2.

Russian media quoted emergency authorities as saying that the quake was felt by Okhotsk islanders, but no casualties or damage were reported and no tsunami alert was issued.

The Japanese side also said it has not received any reports of damage or casualties and no tsunami alert has been issued.