The proliferation of small arms in the war-battered country since the Russian invasion in early 2022 has raised concerns about smuggling both inside Ukraine and among its Western-backed allies.

Russian officials have repeatedly alleged that Western weapons being supplied to the Ukrainian military were ending up on the black market, in the hands of criminal groups or terror organisations.

Police on Thursday afternoon said they had carried out nearly 700 searches, detained 22 people and notified another 38 they are suspects in an illicit weapons smuggling probe.

"Thousands of rounds of various calibres, assault rifles, grenades, machine guns and grenade launchers were seized from the suspects," the police added in a statement.

The police press service also distributed images of the raids that showed canine units and armed officers seizing weapons caches.

Police earlier had announced that several law enforcement agencies were carrying out more than 1,000 searches across the entire country.

The statement said that organisers of the illicit trade could face up to seven years in prison.

The national police had also issued a video showing heavily armed officers preparing to break down a door, seizing ammo and cash.

The raids are the latest efforts by law enforcement to stamp out the illegal distribution of weapons, which has been a concern since Kremlin-backed separatists rose up in eastern Ukraine in 2014.

In October the Security Service of Ukraine said it had tracked down seven arms dealers that were selling weapons including Russian arms taken from the battlefield in four regions of Ukraine.

In September last year, police said they had thwarted an illegal arms operation in the Kyiv region, seizing some 40,000 euros ($41,600) worth of guns and ammunition.

And one month earlier in the western Lviv region, police said they had seized assault rifles, more than 70 pistols, dozens of grenades and almost 49,000 rounds of ammunition, local media reported.

The interior ministry said at the beginning of the full-scale invasion that authorities had distributed more than 25,000 weapons to repel Russian attack in the Kyiv region.

Authorities said since that they had only recuperated a fraction of those weapons.

US officials said early last year there was no evidence of Ukraine misusing the tens of billions in aid.