BEIJING — Communist China on Monday said more than 10 American high-altitude balloons have flown in its airspace during the past year without its permission, following Washington’s accusation that Beijing operates a fleet of surveillance balloons around the world.

The Chinese allegation comes after America shot down a suspected Chinese spy balloon that had crossed to South Carolina from Alaska, sparking a new crisis in bilateral relations that have spiraled to their lowest level in decades.

A Foreign Ministry spokesman, Wang Wenbin, gave no details about the alleged American balloons, how they had been dealt with or whether they had government or military links.

“It is also common for U.S. balloons to illegally enter the airspace of other countries,” Mr. Wang said at a daily briefing. “Since last year, U.S. high-altitude balloons have illegally flown over China’s airspace more than 10 times without the approval of Chinese authorities.”

Mr. Wang said America should “first reflect on itself and change course, rather than smear and instigate a confrontation.”

China says the balloon shot down by America was an unmanned airship made for meteorological research that had been blown off course. It has accused America of overreacting by shooting it down and threatened to take unspecified action in response.

Following the incident, Secretary of State Blinken canceled a visit to Beijing that many had hoped would put the brakes on the sharp decline in relations over the island democracy of Taiwan, trade, human rights and threatening Chinese actions in the disputed South China Sea.

Also Monday, the Philippines accused a Chinese coast guard ship of targeting a Philippine coast guard vessel with a military-grade laser and temporarily blinding some of its crew in the South China Sea, calling it a “blatant” violation of Manila’s sovereign rights.

Mr. Wang said a Philippine coast guard vessel had trespassed into Chinese waters without permission on February 6 and that Chinese coast guard vessels responded “professionally and with restraint.” 

China claims virtually all of the strategic waterway and has been steadily building up its maritime forces and island outposts.

“China and the Philippines are maintaining communication through diplomatic channels in this regard,” Mr. Wang said. China’s Defense Ministry did not immediately respond to a question about the incident.

Adding to tensions, an American fighter jet shot down an “unidentified object” over Lake Huron on Sunday on orders from President Biden. It was the fourth such downing in eight days in a chain of events over American airspace that Pentagon officials contend has no peacetime precedent.

The Chinese balloon shot down by America was equipped to detect and collect intelligence signals as part of a huge, military-linked aerial surveillance program that targeted more than 40 countries, the Biden administration declared Thursday, citing imagery from American U-2 spy planes.

Part of the reason for the repeated shootdowns is a “heightened alert” following the alleged Chinese spy balloon, the head of NORAD and the U.S. Northern Command, General Glen VanHerck, said in a briefing with reporters.

The United States has since placed economic restrictions on six Chinese entities it said are linked to Beijing’s aerospace programs as part of its response to the incident. The House of Representatives also voted unanimously to condemn China for a “brazen violation” of American sovereignty and efforts to “deceive the international community through false claims about its intelligence collection campaigns.”

Mr. Wang, the Chinese spokesman, repeated China’s dismissal of such claims, saying, “the frequent firing of advanced missiles by the U.S. to shoot down the objects is an overreaction of overexertion.”