President Hugo Chavez has accused the United States of flying a spy plane into Venezuelan airspace, and warned that any further intruders will be shot down.

The president said during his weekly TV address that the American plane flew in from Colombia.

"I''ve ordered them to be shot down... We cannot permit this", AP news agency quoted him as saying.

The alleged airspace violation comes amid escalating tensions between Venezuela and Colombia, a close ally of Washington. Chavez has accused the U.S. of planning to invade Venezuela with Colombian help.

Last year, Chavez sent tanks to the Colombian border after Colombian troops raided a rebel base in Ecuador.