2) 'by' is the right option

1) Would you use gunsights or guns' sights in "In 25 years of conflict, one hundred thousand deaths have been estimated, and over 250 thousand Tamils are now under guns' sights/gunsights and under the silence of international society. " option 1) and over 250 thousand Tamils are now under guns' sights and under the silence of international society option 2) and over 250 thousand Tamils are now under gunsights and under the silence of international society I would not use 'under' twice in the same sentence. More of a look and sound thing than grammatically incorrect. not perfect, but "In 25 years of conflict, one hundred thousand deaths have been estimated. Over 250 thousand Tamils remain in the gun-sights (of....who) and under the silence of the international society. you could exchange the number for the written equivalent too 'twenty-five', for example

please