The government then launched Operation Lalang (Weeding Operation), detaining 55 people under the ISA. More were arrested over the next few months. Although most were opposition politicians — including Parliamentary Opposition Leader Lim Kit Siang — a few from BN were included. All BN politicians were released from detention after two months, while those from the opposition remained in custody for much longer. The government later justified these detentions on grounds of security, stating that the detainees had played up the issue of Chinese education to incite racial sentiment. Some of Mahathir's supporters saw this as a vindication of his rejection of the Tunku's "compromise" with the non-Malays, teaching the non-Malays not to criticise the government and its pro-Malay policies.