“The State Emergency Service lost a part of its family,” said its chief, Serhiy Kruk, in a post on Facebook, which said that a paramedic and another person had also been injured in the attack. Experts had removed 7,300 mines in the week to Saturday, the service said in a post on the Telegram social messaging app.

The Ukrainian authorities have placed Kherson’s regional capital city under a weekend curfew because of unspecified threats posed by Russian forces and to facilitate the unimpeded work of Ukrainian law enforcement and military.

Russia claims it thwarted an attack on a regional airfield

Russia’s Federal Security Service, or F.S.B., has accused Ukrainian intelligence of planning a drone attack on an airfield in the eastern Ivanovo region of the country, state media reported on Sunday.

The Russian state news agency Tass cited a statement from the F.S.B. saying that the agency had “thwarted an attempt to carry out an act of sabotage” using drones filled with explosives. The agency, whose Soviet predecessor was the K.G.B., said the attack was “masterminded” by Ukrainian intelligence, according to Tass.

Ukrainian authorities did not immediately comment on the claims, which could not be independently verified. The F.S.B. has long been suspected of blaming others for crimes it commits itself. The allegations come days after explosions over the Kremlin, which Moscow claimed were a drone attack aimed at assassinating President Vladimir V. Putin, without providing evidence. Ukraine has strenuously denied involvement.