Quintus Curtius Rufus, History of Alexander 9.4.7

9.4.7

Quod cum ipsi augerent, hostes extinguerent, nova forma pugnae erat: delebant incolae urbem, hostes defendebant. Adeo etiam naturae iura bellum in contrarium mutat.

He then laid siege to another town, but the defenders made so gallant a resistance that he was repulsed with the loss of many of his Macedonians. He persevered, however, with the siege till the inhabitants, despairing of their safety, set fire to their houses, and cast themselves along with their wives and children into the flames. War then showed itself in a new form, for while the inhabitants were destroying their city by spreading the flames, the enemy were striving to save it by quenching them, so completely does war invert natural relations. The citadel of the town had escaped damage, and Alexander accordingly left a garrison behind in it. He was himself conveyed by means of boats around the fortress, for the three largest rivers in India (if we except the Ganges) washed the line of its fortifications. The Indus on the north flows close up to it, and on the south the Acesines unites with the Hydaspes.