(BSS/AFP) - The US military has "engaged" with bomb disposal experts in Papua New Guinea after a suspicious object was found in a shipping container, Washington`s embassy in Port Moresby said Thursday.

The resource-rich but underdeveloped Pacific nation has defence ties with the United States, as well as Australia.

Papua New Guinea police told local media earlier they had detained four Chinese men after the discovery at a port last week.

China`s embassy said Tuesday the object was a "shell-shaped wine bottle" that "poses no danger at all".

The US embassy refuted that statement in a social media post on Thursday that commended the local police response.

"Following the discovery of a suspicious object in a shipping container in Port Moresby, US Department of War personnel directly engaged with the PNG Explosive Ordnance Disposal unit that examined the object," it said.

"According to publicly reported PNG police findings, the object was an unexploded Chinese-manufactured artillery projectile containing explosives and a fuse, not simply a wine bottle."

"An artillery projectile or a wine bottle? The facts matter," it added.

Australia`s national broadcaster ABC has reported, citing unnamed sources, that police had identified the object as an undetonated 130 mm Chinese Type 59 Artillery Projectile with chemical explosives and a fuse.

The Chinese embassy statement said it was "virtually impossible for an illegal military-grade artillery shell to be smuggled out of China to PNG".

"According to the company involved and following an on-site verification, the object in question -- reported as an `artillery shell` -- is in fact a shell-shaped wine bottle. It poses no danger at all."