On 19 August at Karangan Peris in the Skrang area, Rentap first fought against Brooke's forces. He ambushed the advance trackers of Brooke's reconnoitering troop with a formidable array of war boats and thousands of men on either bank of the river, placed to effectively use spears and blowpipes. With boats and bamboo rafts blocking their retreat, the troop's whiteman leader Mr Stewart, a Malay chief Datuk Patinggi Ali and 30 of his men were killed, and 56 others wounded. This was the first time the Brooke officers saw how devastating the fighting and war by the Iban.