On Thursday, a little over a month after a massive blast devastated Beirut, a raging fire in the Lebanese capital’s port spewed thick plumes of smoke over the city.

Video and images posted online showed flames leaping inside a column of black smoke in the same area where nearly 3,000 tons of ammonium nitrate exploded on Aug. 4. Other images captured the tornado-like swirl of smoke, rising high into the sky before diffusing out across the city where it hung in a cloud.

It was not immediately clear what caused the fire.

However, the director general of the Beirut port told the Lebanese Broadcasting Corporation that the blaze broke out in the building of a company that imports frying oil. It then spread to rubber tires, he said.

The governor of Beirut told residents to evacuate the streets and warned live on LBC that by staying put their lives were in danger and they risked impeding the firetrucks.

Meanwhile, attempts to extinguish the blaze were underway and army helicopters would participate, a spokesperson for the Lebanese army also told the broadcaster.

Beirut residents remain on edge after the enormous blast killed 191 people and injured 6,000 others. It was considered to be one of the biggest non-nuclear explosions ever recorded.