Taipei, April 10 : Chinas military is practising ship-launched strikes on Taiwan from the east, information released by Taiwans Defence Ministry on Monday indicated, as Beijings retaliatory military drills entered their third day. The Ministry did not give the positions of People's Liberation Army (PLA) ships it had detected, but a map of PLA aircraft detections show four J-15 fighter jets east of Taiwan, in the western Pacific, on Saturday, the Guardian reported. The J-15s have never been seen inside Taiwan's air defence identification zone (ADIZ) before, and are known to be launched from two PLA aircraft carriers, including the Shandong which had been tracked by Taiwan and Japan sailing past Taiwan into waters to its south-east late last week. On Monday, Japan confirmed its military had responded to the drills, scrambling jets in response to the PLA's aircraft launches. On Saturday, Beijing launched three days of military exercises targeting Taiwan in response to Taiwan's President Tsai Ing-wen meeting US House Speaker Kevin McCarthy in Los Angeles last week. The drills have not matched the scale of those launched in retaliation to a Taipei visit by McCarthy's predecessor, Nancy Pelosi, which included missile launches, but do appear to show an escalation in the Chinese military's training for strikes on Taiwan, observers said, the Guardian reported. Taiwan's Defence Ministry detected 70 PLA aircraft and 11 ships inside its ADIZ. The ADIZ is a large area monitored for defence purposes, and the PLA assets did not enter sovereign Taiwan territory. However the Ministry said 35 of the planes had crossed the median line -- a de facto border in the international waters of the Taiwan Strait. The launch of J-15s suggested the PLA was "practising strikes on Taiwan from an encirclement-style posture", independent defence analyst Ben Lewis told the Guardian. /IANS