A light plane with four people on board disappeared in the Swiss Alps, rescue officials said Monday.
The single-engine Piper aircraft went missing late Sunday over the southern Swiss canton (state) of Ticino, Switzerland's air search and rescue service said.
The plane was on its way from the Italian city of Parma to Zurich in Switzerland when it lost contact around 1900 local time (1700 GMT), officials said.
A helicopter search late Sunday proved fruitless. Officials resumed the search from the ground Monday.
The United States and NATO are conducting provocative activities both in airspace and waters of the Black Sea, Russian Defense Minister Sergei Shoygu said