By the order of the Sultan, Hashim and his brother Badruddin together with their family were assassinated in 1846. One of Badruddin's slaves, Japar, survived the attack and intercepted HMS "Hazard", which brought him to Sarawak to inform Brooke. Enraged by the news, Brooke organised an expedition to avenge Hashim's death with the aid of Cochrane from the Royal Navy with "Phlegethon". On 6 July 1846, Sultan Omar Ali Saifuddin II complained through a letter about the discourtesy of HMS "Hazard" and invited Cochrane to ascend the capital with two boats. "Phlegethon" and other vessels then moved up to the river on 8 July where they were fired on from every position with slight damage. Mahkota and the Sultan retreated upriver while most of the population fled upon their arrival at Brunei's capital, leaving the brother of the Sultan's son, Pengiran Muhammad, who was badly wounded and Pengiran Mumin, an opponent of the Sultan's son who despised the decision of his royal family to be involved in conflict with the British. The British destroyed the town forts and invited the population to return with no harm to be done to them while the Sultan remained hiding in the jungle. Another expedition was sent to the interior but also failed to find the Sultan. Brooke remained in Brunei with Admiral Rodney Mundy and HMS "Iris" along with "Phlegethon" and HMS "Hazard" while the main expedition continued their mission to suppress piracy in northern Borneo.