A Chinese spy balloon has been detected above the sensitive waters of the Taiwan Strait before disappearing, Taiwan's Defense Ministry said Thursday.

The episode, reminiscent of the high-altitude reconnaissance balloon seen over the U.S. earlier this year, comes amid heightened regional tensions and sparked renewed concerns about China's surveillance activities.

The U.S., which said the Chinese spy balloon had violated American territorial sovereignty, shot down the craft off the South Carolina coast in early February. Beijing said it was an errant weather device.

Taiwan's Defense Ministry said it detected the surveillance balloon at 11:52 a.m. local time, approximately 101 nautical miles southwest of the northern port city of Keelung, at an altitude of 21,000 feet.

"The balloon headed east and disappeared at 12:55 [p.m.]," the ministry said.