Eleven Chinese naval vessels were detected around Taiwan, Taipei's defence ministry said on Wednesday, the highest number this year as a row between the island and China over a fatal fishing boat incident drags on.

A Chinese speedboat carrying four people capsized on 14 February near Taiwan's Kinmen islands while being pursued by the Taiwanese coast guard, throwing all on board into the water.

Two of the crew died and two others were rescued and temporarily detained in Kinmen -- a territory administered by Taipei but located just five kilometres (three miles) from China's city of Xiamen.

The incident occurred against a backdrop of already-heightened tensions between China and Taiwan, a self-ruled island that Beijing claims as part of its territory.

A survivor reportedly claimed the boat was "rammed" after returning to the mainland, though Taiwan insists the coast guard was following legitimate procedures.

In the 24 hours leading up to 6:00 am on Wednesday (2200 GMT Tuesday), Taiwan's defence ministry said China sent 15 warplanes, 11 naval vessels and one balloon into the waters and skies around the island.

The ministry said at least 15 more Chinese warplanes had been detected since then.

The number of Chinese naval ships was more than the usual four to six spotted in a 24-hour window, and the highest so far this year, according to Taiwan's official data.

In December, 11 Chinese naval vessels were detected around Taiwan in the run-up to its January presidential elections -- won by Lai Ching-te, whom Beijing has called a "separatist".

On Monday, one Chinese maritime surveillance ship and four Chinese coast guard boats briefly entered prohibited or restricted waters around Kinmen, according to Kuan Bi-ling, minister of Taiwan's Ocean Affairs Council, which supervises the coast guard.

Beijing has accused Taiwanese authorities of "seeking to evade their responsibilities and hide the truth" about the 14 February incident, while a Taiwanese coast guard official has said the boat involved was zigzagging, "lost its balance and capsized" while trying to evade a patrol vessel.