Ukraine's State Security Service (SBU) has rejected the statement by the Russian Federation's Federal Security Service (FSS) about the deployment of Ukrainian saboteurs to Russia-occupied Crimea.

"Ukraine does not seize or return by force its territory now and will not do so in the future. I can tell you this," SBU adviser Yuriy Tandit told the Interfax-Ukraine news agency on Friday.

"That's why it is possible from this standpoint to turn the statement by the FSS or the [Russian] ministry of defense on its head. We will not use force to return our territory. It is our territory and we have rights to it," he said.

The SBU adviser said that "citizens of Ukraine live in Crimea and we cannot and do not have the right to make them suffer or launch an attack on someone there."

"We refute the information [of the Russian FSS about a so-called attempt by a diversionary group made up of crack troops from the Ministry of Defense of Ukraine]. What is the motive? We are not attempting to return our territory by force," Tandit said.

As earlier reported, Russia's FSS on Wednesday said it with support of other defense and security structures had averted a breakthrough by groups of saboteurs and terrorists into Crimea from the territory of Ukraine.

"In the early hours of August 8, 2016, special units of the Ukrainian Defense Ministry made another two attempts to break through using groups of saboteurs and terrorists, which were averted by the defense and security units of the Russian Federal Security Service and the interacting agencies," the report said.

According to the FSS, "the breakthrough attempts were covered by a massive attack from the neighboring state and armored vehicles of the Ukrainian Armed Forces, a Russian Defense Ministry serviceman was killed in the skirmish."

The Federal Security Service said a criminal case has been opened on the basis of the results of the operational search activities and the combat measures conducted by the investigative department of the Federal Security Service's Department for Russia and the Republic of Crimea and Sevastopol and additional operational and investigative activities are being conducted.

"Security has been tightened in places where many people gather and in recreation places, and also to protect critical infrastructure facilities. The border regime on the Ukrainian border has been intensified," the Federal Security Service said.