Massive explosion in Beirut rocks buildings for hundreds of feet; 'very high number of casualties' — source remains unclear

A major explosion in Lebanon's capital of Beirut shattered windows and rocked buildings for hundreds of feet, according to reports.

What's happening?

Disclose shared a video on Twitter, captioning it, "Massive explosion in Beirut. Al-Mayadeen reports the explosion in Beirut is not an act of terrorism according to preliminary information. But holy moly ... what is the cause of something like this?!"

The outlet also reported "VERY HIGH number of casualties reported by the Lebanon health minister as a result of the explosion in Beirut (Sky News)."

The explosion took place Tuesday, according to The Guardian, and its source is not clear at the time of this writing.

The outlet reports that the explosion "rocked central Beirut" and "shattered windows, knocked down doors, and shook buildings several hundred feet away."

"An enormous cloud of smoke could be seen from across the city and witnesses said there were reports of a fire and several small explosions at the port preceded the large blast after 6pm on Tuesday," the outlet continued.

The BBC reported that there were several explosions — one smaller one following the massive blow that shook buildings for blocks.

The outlet reported on "unconfirmed reports" of a second blast, and points out that "A UN tribunal is due to issue its verdict in the trial of four suspects in the murder by car bomb of [Lebanon ex-PM Rafic Baha El Deen Al ]Hariri."

The four suspects are reportedly members of Iranian-backed Hezbollah group.

Reports have emerged that the possible second explosion reportedly took place at the Hariri residence in Beirut.

The verdict is due on Friday.

Local state-run media report that the explosion source was a "major fire at a warehouse for firecrackers near the port." The report said large numbers of people were wounded.

CNN reported that "[m]any buildings were damaged by the explosion, including the headquarters of ... Hariri."

Eyewitnesses also say that residences as far as 10 kilometers away were damaged due to the blast.

Internet outages abound

Reports are also emerging about a "significant internet outage" following the blast.

A tweet read, "Confirmed: Real-time network data show significant internet outage in #Lebanon following reports of blast near #Beirut impacting ability to contact eyewitnesses; circumstance and cause remain unclear; incident ongoing; see live report for updates."

This is a developing story and will be updated as events warrant