In April 1955, the Kashmir Princess, a chartered aircraft owned by Air India was damaged in midair by a bomb explosion and crashed into the South China Sea while en route to Jakarta, Indonesia. Sixteen of those on board were killed; three survived. 

The explosion was apparently an assassination attempt on Chinese Premier Zhou Enlai, who missed the flight, possibly due to advance information or to a medical emergency.

The Chinese government concluded that the Kuomintang (a political party in the Republic of China in Taiwan) was responsible for the bombing.

Source: Wikipedia