Ukraine, which has two major ports on the Sea of Azov through which it exports steel and agricultural products, has alleged that the bridge is being used by Russia as part of a creeping hybrid blockade of Ukrainian ports in the Azov Sea, and that Russian inspections of ships have risen sharply since the bridge opened in May 2018, some being forced to wait for three days before being allowed through. The main span of the bridge is above sea level; the Ukrainian maritime authority says many ships are too big to pass safely under the bridge. The bulk carrier "Copan" (deadweight tonnage 17,777 tons) solved this problem by cutting off the top of her mast. On 26 October 2018 "The Globe and Mail", citing Ukrainian sources, reported that the bridge had reduced Ukrainian shipping from its Sea of Azov ports by about 25%. In November 2018 the area near the bridge became a site of the Kerch Strait incident, in which the Russian navy claimed that three Ukrainian vessels entered Russian territorial waters. Russian forces seized the vessels and arrested their crews. During this time, passage through the Strait was blocked by a large cargo ship, placed under the bridge to prevent passage of other craft. In response, Ukraine declared martial law in some regions of the country for 30 days.