“We would like to inform you of a temporary suspension of vessel traffic to and from (the ports). The current ban is in force on October 26, but it is possible that it will be extended,” the consultancy said on the Telegram messaging app.

Ukrainian officials were not immediately available for comment.

The consultancy said a de facto suspension had already been in place for two days at the behest of the military which cited a threat from increased Russian military aviation activity in the area.

Russia’s President Vladimir Putin said last week that he had ordered Russian warplanes with Kinzhal missiles to patrol the Black Sea. 

Ukraine launched a “humanitarian corridor” for ships bound for African and Asian markets in August to try to circumvent a de facto blockade in the Black Sea after Russia quit a deal that had guaranteed Kyiv’s seaborne exports during the war.

Later, a senior agricultural official said the route would also be used for grain shipments.

Ukrainian officials and shipping sources say more than 40 cargo vessels have entered the corridor so far and 1.5 million metric tons of cargo have left Ukrainian seaports via the corridor.

Grain, oilseed, vegetable oils, meals have dominated the shipments.

Ukrainian agricultural producers this week said the new route could enable exports of up to 2.5 million tons of food a month, almost offsetting the impact of Russia’s decision to quit the previous U.N.-brokered deal.

The first deputy farm minister Taras Vysotskiy said on Wednesday grain shipments through the corridor could exceed one million tons in October. 

(Reporting by Pavel Polityuk; editing by Tom Balmforth)