The 2014 political crisis in Ukraine rapidly engulfed Crimea where pro-Russian separatist sentiment was strong. When the Russian Government determined to seize Crimea, specialist Russian military units appear to have played the central role. In March, the Ukrainians claimed that units of the 18th Motor Rifle Brigade, 31st Air Assault Brigade and 22nd Spetsnaz Brigade were deployed and operating in Crimea, instead of Black Sea Fleet personnel, which violated international agreements signed by Ukraine and Russia. Nevertheless, at minimum the Black Sea Fleet played a supporting role including with respect to preventing the departure of Ukrainian naval vessels from Crimea. Other sources suggested that the 810th Naval Infantry Brigade of the Fleet was also involved.