KIEV, August 11. /TASS/. Ukrainian President Pyotr Poroshenko ordered on Thursday to put on full combat alert all units on the border with Crimea and on the contact line in Donbass.

"I have ordered to put on full combat alert all units in the border areas with Crimea and on the contact line in Donbass," Poroshenko said after a meeting with the leadership of Ukraine's security agencies and the Foreign Ministry.

The move comes in the wake of alleged attempted terrorist attacks in Crimea. Russia’s Federal Security Service (FSB) reported on August 10 that it had prevented terrorist acts in Crimea that had been prepared by the Main Intelligence Department of the Ukrainian Defense Ministry.

Poroshenko also gave instructions to the country’s security, border guard and other agencies.

"Special requirements must be set for border guards in the areas of the administrative border with the temporarily occupied Crimea and on the contact line in Donbass," the Ukrainian president said.

The Ukrainian border guards have been ordered to enhance pass control at check points while the National Guard and the national police have been instructed to heighten the protection of strategic facilities.

Ukraine’s Security Council chief has been instructed to hold an emergency meeting of the Anti-Terror Center and bring the necessary tasks to its notice.

Also, the Ukrainian foreign minister has been instructed to hold meetings with representatives of foreign diplomatic missions in Ukraine and inform them of the latest developments on the border with Crimea and on the contact line in Donbass, the press office of Ukraine’s president reported.

One FSB officer was killed during the operation to detain terrorists on August 10. Later, a serviceman of Russia’s Defense Ministry was killed as the saboteurs made a second attempt of intrusion. Russian President Vladimir Putin said on Wednesday that Russia would do everything to ensure the security of citizens and infrastructure in Crimea.

Twenty improvised explosive devices containing more than 40 kilograms of TNT equivalent, ammunition, fuses, antipersonnel and magnetic mines, grenades and the Ukrainian armed forces’ standard special weapons were found at the scene, the FSB said.

Russian President Putin called as silly and criminal the attempt of a subversive act by the Ukrainian special services in Crimea aimed at distracting attention from Ukraine’s internal problems and from the authorities robbing their people.

Ukraine’s President Pyotr Poroshenko and the Foreign Ministry have rejected Moscow’s accusations, calling the alleged saboteurs’ detention a provocation.