A blast on a key bridge linking Russia with Crimea last weekend caused major damage to the prestige project of Russian President Vladimir Putin. Authorities have now arrested eight people who they claim were involved.

Media reports say five Russians and three people from Ukraine and Armenia were detained.

Russian security officials claim the Ukrainian Defence Ministry organized the explosion on the 19-kilometer bridge. But Ukraine has not officially confirmed its involvement in the blast.

Russia has retaliated to the explosion by firing dozens of missiles into Ukrainian cities, and there are reports that attacks on civilians are continuing for a third day.

They have killed at least 26 people and wounded over 100 since Monday.

Meanwhile, the attacks are leading more than 50 countries to gather on the sidelines of a NATO meeting on Wednesday.

They will discuss bolstering Ukraine's air defenses after the most intense missile strikes since the start of the war.