The explosion occurred early on Sunday and videos shared on social media showed a large fire at the blast site.
Lebanon is currently experiencing a severe fuel shortage and the past week has seen multiple incidents of tankers being hijacked.
Hospitals have warned that they are low on fuel and may be forced to shut down.
Hariri is the leading Sunni Muslim politician, the dominant religion in Lebanon’s north, and has been in open opposition to Lebanese President Michel Aoun.
Gebran Bassil, who heads the party founded by Aoun, wrote on Twitter that “our hearts are with families in Altalil and Akkar tonight.”