Tension and confusion over the origin of a deadly Russian-missile that hit in Polish territory.

Poland has placed its military on high-alert, after the blast in a village near Ukraine's border killed two people. Both Russia and Ukraine are flatly denying responsibility.

US President Joe Biden and Nato leaders have declared their support in helping Poland investigate the cause.

Newshub European correspondent Lisette Reymer says caution is critical, to determine whether the strike was intentional. Lisette Reymer suggests it could be the result of Ukrainian air-defence.

LISTEN ABOVE

• 'This war must end' Jacinda Ardern condemns missile strike in Poland
• 'Crisis situation': Russian missiles hit Nato-member Poland, killing two
• Biden says 'unlikely' missile was launched from Russia after emergency G7 and Nato meeting