Major US newspapers have suggested Ukrainians were involved in the explosions that rocked a Russian air base in Crimea on Tuesday.

Russia unilaterally annexed the region in southern Ukraine eight years ago. Russia's defense ministry denied the air base was attacked. It said the explosions were caused by detonation of aircraft ammunition.

Ukraine has not officially mentioned involvement. But on Wednesday The Washington Post quoted a Ukrainian government official as saying the attack was the work of Ukrainian special forces.

The New York Times also reported that a senior Ukrainian official had said the attack had "involved partisan resistance forces loyal to the government in Kyiv."

Russia claimed no aircraft were damaged. But the Institute for the Study of War, a US think tank, said on Wednesday that satellite imagery showed at least eight Russian aircraft were destroyed.

The institute also suggested that the Russian side remained confused about Tuesday's attack and that it may "not yet understand how or from exactly where Ukrainian forces conducted the attack."

Last year, Ukraine launched an international conference to which it invited the leaders of friendly countries and others with the aim of regaining control of Crimea. Ukraine says it will hold the conference again this year on August 23.

Ukrainian President Volodymyr Zelenskyy said on Tuesday that the Russian war against Ukraine began with Crimea and must end with Crimea.

Fighting over the south of Ukraine may become even more intense.