The deaths of people during the Israeli military attack on humanitarian aid ships en-route to Gaza are irreversible and unmotivated, Russian President Dmitry Medvedev said on Tuesday, according to RIA Novosti.

The Israeli military stormed the ships, carrying some 10,000 tons of aid to the Hamas-run Gaza Strip and 700 human rights activists in neutral waters in the Mediterranean Sea on Monday.

"It is necessary to perform an extremely thorough investigation," Medvedev said. "However, in any case, the deaths of people are irreversible and absolutely unmotivated," he continued.

Nine activists have been confirmed dead but Arab media reports put the toll at close to 20. Dozens were reported injured. The international community has widely condemned Israel, with Turkey recalling its ambassador.