Remnants of a Chinese rocket crashed into the Indian Ocean on Sunday in one of the largest uncontrolled re-entries of a spacecraft in history.
No one is believed to have been injured, but the incident prompted Nasa to criticise China for "failing to meet responsible standards regarding their space debris" and a lack of transparency.
People in Jordan, Oman and Saudi Arabia reported spotting the debris in the dawn skies, which crashed into the ocean at 0224 GMT (2.24pm Sunday, NZ time) near the Maldives, according to coordinates reported by Chinese state media.
China's space agency said that most of the core section of its Long March 5B rocket burned up on re-entry into Earth's atmosphere.
The news ended days of speculation about where debris from the rocket's core section, which was 30 metres long and weighed 21 tonnes, would land.
Chinese state media had dismissed worries that the rocket was out of control and could cause damage as "Western hype".
But Nasa's administrator, Bill Nelson, said in a statement: "China is failing to meet responsible standards regarding their space debris".
"Spacefaring nations must minimise the risks to people and property on Earth of re-entries of space objects and maximise transparency regarding those operations," said the former senator and astronaut.
"It is critical that China and all spacefaring nations and commercial entities act responsibly and transparently in space to ensure the safety, stability, security, and long-term sustainability of outer space activities."
While the debris was most likely to land on water – which covers most of the Earth's surface – it could have potentially landed at any point as far north as Beijing, Madrid and New York, and as far south as southern Chile and Wellington.
"An ocean reentry was always statistically the most likely," said Harvard astrophysicist Jonathan McDowell on Twitter. "It appears China won its gamble… But it was still reckless."
He said it was the joint fourth biggest uncontrolled re-entry on record.
Most countries have tried to design their spacecrafts to avoid uncontrolled re-entries since large chunks of the Nasa space station Skylab fell from orbit and landed in Australia in 1979.
"It makes the Chinese rocket designers look lazy that they didn't address this," McDowell told Reuters.
While the module separated from the launcher to continue its journey as planned, the launch vehicle's core section also reached orbit.
China's military-backed space programme has not explained why the section didn't fall back to earth soon after separating from its payload, which is usual in such operations.
The Long March 5B's first launch in May last year also ended with an uncontrolled re-entry.
Debris from what had been an 18-tonne core section passed over the US and landed in the Atlantic Ocean off West Africa, with pieces also damaging several buildings in the Ivory Coast.