Three Colombian students were killed in a working class neighborhood when the explosives that they were handling while making homemade bombs detonated, police said.
General Luis Eduardo Martinez, head of the Bogota police, told reporters that eleven other people were hospitalized following the blast, including another student with serious injuries.
The students, from the Bogota District University, had some 10 kilos (22 pounds) of explosives and were making "potato bombs," Martinez said.
In the past students have hurled these bombs at police during protests.
One of those wounded was the mother of one of students killed in the blast, Martinez said.
In the home police found propaganda documents supporting the leftist Revolutionary Armed Forces of Colombia (FARC) guerrillas, as well as the M-19, a leftist group that demobilized in 1989. Bogota Mayor Gustavo Petro is a former M-19 member.