New Delhi, Jan. 15 -- A massive explosion followed by a major fire struck the center of Dutch city of Utrecht, Netherlands, on Thursday, leaving at least four individuals injured, officials reported.

The Dutch news agency ANP quoted a local fire department spokesperson describing the event as a "gigantic explosion", as reported by news agency AFP.

"Several buildings collapsed after the explosion. Four people were injured. They were taken to the emergency hospital ... for treatment," the local authorities said on their website.

The fire was still raging on Thursday evening.

The specific cause of the blast is currently unknown, and authorities are still determining if there are additional casualties. As emergency crews converged on the ...