Polish media reports a blast at a grain plant near Ukraine, and Poland’s government calls a crisis meeting.

A deadly explosion took place Tuesday at a grain processing facility in Poland near the border with Ukraine, according to Polish media outlets, and top government officials called an emergency meeting.

The cause of the explosion in the village of Przewodow, about four miles north of the Ukrainian border, was not immediately clear. A Polish radio station reported that two people were killed.

At a Pentagon briefing in Washington, Brig. Gen. Patrick S. Ryder said that the Defense Department was aware of media reports saying that two Russian missiles had landed in Poland, but said that U.S. defense officials had no corroborating information.

Poland’s prime minister, Mateusz Morawiecki, and president, Andrzej Duda, convened a meeting of the National Security Council in response to a “crisis situation,” a government spokesman, Piotr Mueller, told reporters.

The explosion came on the same day that Russia launched a widespread missile attack on Ukraine, with roughly 100 missiles that were aimed primarily at the country’s electrical infrastructure. Ukraine’s Volyn region, where Russian rocket strikes were reported on Tuesday, lies across the border from Przewodow.

Ukrainian officials said the country’s air defense systems had shot down 70 of the incoming missiles; witnesses said a fragment of one destroyed missile struck a residential building in Kyiv, killing one person.