according to international laws, are soldiers of any country allowed to storm a ship in international waters? Because if they are not, it's a piracy act and the people on board could even be entitled to shoot (and they did'nt) the intruders, and the "violent reaction" doesn't justify in any way the shooting of civilians. On the contrary if they are entitled according to internationa laws, it's different, it's a sort of self defence though it seems an excess of self defence.
Protests in southern Syrian city after Druze cleric's death (AP)
from the article: Straight into the trap