KIRKLAND, Wash. -

 Kirkland Police say an explosion at an apartment complex may have been caused by malfunctioning equipment used in marijuana production.

KIRO-TV reports two men were injured in the explosion just after 9 p.m. Wednesday.

Kirkland police would not share more information about the explosion.

Three people were hurt in a similar incident in August in Mount Vernon, where butane was being used to extract hash oil from marijuana.