United Nations, June 18 : UN Secretary-General Antonio Guterres has strongly condemned an attack on a secondary school in western Uganda reportedly perpetrated by the Allied Democratic Forces (ADF) group, said his Deputy Spokesman. Ugandan authorities said on Saturday that ADF rebels attacked the Lhubirira secondary school in Mpondwe on the border with Congo on Friday night, killing at least 37 students. At least eight students remained in critical condition. Six students were in the hands of the rebels. Those responsible for this appalling attack must be brought to justice, said Farhan Haq, the Deputy Spokesperson, in a statement as quoted by Xinhua news agency report. The Secretary-General extended his heartfelt condolences to the families of the victims and the government and people of Uganda, and called for the immediate release of those abducted, said the statement. Guterres reiterated the importance of collective efforts, including through enhanced regional partnerships, to tackle cross-border insecurity between Congo and Uganda and restore durable peace in the area, it added. The ADF is a Ugandan rebel group that is holed up in the jungles of eastern Congo. It is a branch of the Islamic State in Central Africa. The rebel group is blamed for causing havoc in villages in eastern Congo. The Ugandan military and their Congolese counterparts launched joint operations against the rebel group in November 2021. /IANS