Baghdad, Iraq (CNN) -- A large power generator in a busy market in central Basra exploded Saturday evening and sparked a fire and secondary blasts that killed dozens, police chief Gen. Adel Daham said.
Daham said the explosion in the Al-Ashar commercial district led to a huge fire and explosions at nearby smaller generators. Daham said many others were wounded.
Police didn't know whether the explosion was a terrorist attack or the result of an electrical spark or malfunction, he said.
Other police officials had a different account of the power generator blast, tying it directly to a bomb. Conflicting reports on incidents are common in Iraq.
The officials said a car bomb and two roadside bombs killed 16 and wounded 44 in Al-Ashar.
The first explosion was a car bomb near a bus station; the second was a roadside bomb at an intersection; the third occurred in a busy street when the power generator that supplies a number of stores and shops was hit by a bomb that led to a huge fire, those officials said.
Iraqi security forces sealed off the area and started to investigate the explosions.
In Mosul, a suicide bomber wearing an explosive vest approached an Iraqi police foot patrol Saturday evening and detonated his explosives, killing one police officer and wounding five others, police said.
Meanwhile four Iraqi police officers were killed and eight others wounded during a raid at a home in southwestern Baghdad, Interior Ministry officials said.
The incident happened Friday night after police got a tip about militants using a home to store weapons. Suspects fired on police as they arrived at the home, triggering an hour-long shootout. The suspects fled from the scene. Police found grenades, machine guns and pistols equipped with silencers in the home.
In a separate incident in northwestern Baghdad, gunmen attacked a police vehicle, killing one officer and wounding another.
CNN's Mohammed Tawfeeq contributed to this report.