The Polish government said that a Russian-made missile killed two of its citizens in a small town near the border with Ukraine on Tuesday. Poland’s government convened an emergency security and defense meeting and agreed to increase its military readiness. The country’s foreign minister summoned the Russian ambassador and demanded an explanation for the deadly blast near the southeastern town of Hrubieszów.

The incident in the territory of a NATO country raised fears that President Vladimir Putin’s war on Ukraine could spread and escalate a regional conflict into a wider war.