An unidentified white object was spotted in the skies above Costa Rica on Thursday as the US military reported tracking a suspected Chinese hot-air surveillance balloon flying over the northern United States.
On Friday, the Pentagon confirmed reports that a similar balloon was "transiting Latin America", without specifying its location.
"We now assess it is another Chinese surveillance balloon," Pentagon spokesman Pat Ryder said.
Pictures and videos of the object seen from Costa Rica were shared on social media — with some users in the country speculating that it may have come from space.
Twitter user Eduardo Costa said the “UFO was also seen in Costa Rica” while Manuel Hernandez said it could be seen from the towns of Zapote and Grecia in the Alajuela Province.
The Centre for Research in Atomic, Nuclear and Molecular Sciences (Cicanum) at the University of Costa Rica regularly launches helium-inflated balloons, according to La Nation newspaper, but researchers at the institution said they had not launched a balloon on Thursday.
“We always do it in co-ordination with Civil Aviation, through a project with Nasa for the validation of satellite instruments and this balloon that was seen today does not really belong to us,” said Cicanum director Elian Conejo.
He said the last one released by the institution was on January 27.
He said the type of balloon spotted on Thursday was a “tethered balloon” which could have been used for meteorological measurements.
The discovery of the Chinese balloon over the US prompted Secretary of State Antony Blinken to postpone his planned visit to China at the weekend.
China on Friday acknowledged launching the high-altitude balloon, saying it was used for weather research and had been inadvertently blown off course.
A senior defence official told Pentagon reporters that the US had “very high confidence” that the balloon was flying over sensitive sites to collect information.
The Pentagon confirmed on Thursday it was tracking a balloon spotted on the Canadian border a few days previously. It later entered US airspace in the state of Montana.
The US government “has detected and is tracking a high-altitude surveillance balloon that is over the continental United States right now”, Gen Ryder said.
The sighting in North America sparked concerns over surveillance and intelligence gathering.
“Once the balloon was detected, the US government acted immediately to protect against the collection of sensitive information,” he said.
He said similar balloon sightings have occurred in recent years.
NBC first reported the news, with defence officials saying leaders had debated shooting it down.
AP later reported that the military had decided not to shoot it down because of possible debris.