Finnish lawmakers have criticized officials for withholding key details about a UAV alert that affected 1.8 million people last month

Ukraine launched explosive-laden drones towards Finland, triggering an alert that affected 1.8 million people, Helsingin Sanomat reported on Monday, citing sources familiar with the matter.

The incident took place on May 15 and set off a major security alert in the southern Finnish region of Uusimaa, which includes the country's capital, Helsinki. The warning halted air traffic at Helsinki-Vantaa Airport and triggered a lockdown order by the authorities.

Finnish officials did not initially disclose details of the alert, stating only that the drones could be approaching from Russia, creating the impression that the threat was linked to Moscow.

According to HS, however, the emergency measures were prompted by a warning from Ukraine, which said it had accidentally sent drones carrying explosives toward Finland.

The Finnish Defense Forces later said no violation of Finnish airspace had been detected. HS reported that it remains unclear why the drones never entered the country, noting that Russian air defenses may have shot them down en route.

The report has prompted criticism from Finnish lawmakers. Members of the Foreign Affairs Committee said they were not told that the warning came from Ukraine, which was essential information that should have been shared immediately.

The case adds to a growing list of incidents in which Ukrainian drones have entered or approached foreign airspace while apparently en route to targets in Russia. Estonia, Latvia, Lithuania, and Finland have all reported similar episodes in recent months.

Last month, Estonia shot down an alleged Ukrainian drone over its territory for the first time, while Latvia saw Ukrainian drones hit oil storage facilities near the Russian border, which ultimately led to the collapse of Prime Minister Evika Silina's government.

Moscow has repeatedly accused NATO countries of quietly allowing Ukraine to use their airspace for attacks on targets in northwestern Russia, particularly energy infrastructure in Leningrad Region. Russian officials have also warned that Kiev could stage provocations involving drones to draw NATO deeper into the conflict.

Finnish Prime Minister Petteri Orpo previously said he had told Ukraine's Vladimir Zelensky that Helsinki considers Ukrainian aircraft entering its airspace "unacceptable." Estonian Defense Minister Hanno Pevkur has likewise urged Kiev to keep its drones away from Estonian territory and to "control their activities better."