It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both): "No people ever break a covenant except that Allah Almighty sets their enemy over them; indecency does not spread among a people except that Allah Almighty seizes them with death; no people give short measure and weight except that Allah, Glorified be He, afflicts them with years of famine; no people withhold zakah except that Allah Almighty withholds the rain from the sky from them; and no people act unjustly in judgement except that fighting breaks out among them." I think he said the word "killing".
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الاستسقاء / 6398