A thought. Note last line - of course we would never let a civilian vessel carrying mines into our harbors. Brought to you by the same department that keeps out TB patients...
China has thousands of contact mines based on old Soviet technology, but it also boasts newer magnetic and acoustic combination types. The export of EM-52 rocket boost rising mines to Iran several years ago highlighted modern advances in PLAN naval mines. The EM-52 can be laid in waters down to 110 meters deep, and it has an electronic trigger for its 140-kilogram warhead. Soviet ADM or MDM series mine copies are common, and they can have air-, ship- or submarine-launched variants.
The units to lay mines off of target areas, such as Taiwan ports, likely would not be mine warfare vessels. The PLAN has several options among other naval assets. About 150 maritime patrol aircraft and naval bombers can carry several mines. For example, China’s H-5 bomber can carry six Chinese copies of the ADM-500 type mines. More than 90 PLAN submarines can sow mines in complete secrecy. Earlier Type 033 Romeo boats can carry 28 mines, and newer diesel and nuclear boats can carry 32 mines each. A variety of surface warships are equipped to lay mines. The modern 24 Jianghu frigates can carry 60 mines, and older frigates and 60 Hainan patrol craft can carry 30 mines each. The 15 large Luda-class guided missile destroyers can carry 38 mines, and more than 300 Shanghai II patrol boats can carry 12 mines each. Of note is the fact that most sea mines laid worldwide since 1950 have been by merchant ships, fishing trawlers or junks. China has thousands of these vessels available.