In 1872, Raja Mahadi gained the support of a number of Malay chiefs, some of them members of Selangor Royal family. Raja Asal and Sutan Puasa, the leaders of Mandailing diaspora in Selangor, also switched their support to Raja Mahadi's side. Raja Mahadi's forces attacked Kuala Lumpur, and Raja Asal laid siege to Bukit Nanas, where Tengku Kudin's forces of 500 soldiers and European mercenaries were stationed.