KIEV (Reuters) - Grain shipments from Ukrainian ports on the Azov Sea could fall if Russia commits more aggressive actions, although the impact would be limited, acting Ukrainian Agriculture Minister Maksym Martyniuk said on Tuesday.

He also said freight prices and insurance company costs could rise, but not in short term.

Russia seized three Ukrainian naval ships and took their crew prisoner at the weekend, prompting Ukraine’s President Petro Poroshenko to say there was now an “extremely serious” threat of a Russian land invasion.