At least six people were wounded when a homemade bomb tore through a song and dance contest in this southern Philippines city, officials said on Monday.
Four of the six victims were teenagers who were treated in hospital, said police investigator Viviano Luna.
The blast occurred late on Sunday at the city square during the amateur singing and dancing contest, Luna told reporters.
Ordnance experts recovered fragments of what appeared to be an improvised explosive device, said the local army commander Major General Nehemias Pajarito.
"The police and the military authorities are looking into the motive of the attack," Pajarito said.