On 2 March 2009, however, Vieira was assassinated by what preliminary reports indicated to be a group of soldiers avenging the death of the head of joint chiefs of staff, General Batista Tagme Na Wai, who had been killed in an explosion the day before. Vieira's death did not trigger widespread violence, but there were signs of turmoil in the country, according to the advocacy group Swisspeace. Military leaders in the country pledged to respect the constitutional order of succession. National Assembly Speaker Raimundo Pereira was appointed as an interim president until a nationwide election on 28 June 2009. It was won by Malam Bacai Sanhá of the PAIGC, against Kumba Ialá as the presidential candidate of the PRS.