DOROHUSK, Poland — Three times in one day, phones lit up across this Polish border community with a warning: A drone or a missile could cross from Ukraine, and residents should stay vigilant in case they might need to take cover.

Above the village of Dorohusk in eastern Poland, vapor trails cut across the pale blue sky and military helicopters rumbled overhead. Just 2 kilometers (1.24 miles) away, traffic at the border crossing into Ukraine was suspended three times, and staff were even evacuated once.

The alerts and disruptions on Thursday came as The Associated Press was visiting the village. They reflected a new reality along Poland’s eastern frontier, where the war in Ukraine — now 4 1/2 years old — has felt increasingly close.

Russia isn’t at war with Poland, but over the past few years European leaders say it’s mounted a series of so-called hybrid attacks to pressure to pressure adversaries in the West and NATO that include sabotage, disinformation and cyberattacks. Poland is worried that the drones or missiles strikes could spill over from Ukraine, whether by accident or as part of a Russian strategy of ambiguous attacks.

The anxiety intensified after two Russian drones exploded on the Ukrainian side of the Dorohusk-Yahodyn crossing in the early hours of Sept. 13. The explosions could clearly be heard in Dorohusk.

“There is new restlessness and fear because you could hear those explosions very well on that night in our village,” said Wojciech Sawa, the Dorohusk mayor. “We had never had something like that before. This was the first time the sirens wailed.”

Polish Prime Minister Donald Tusk warned on Sept. 17 that Russia was planning hybrid strikes with drones or rockets on European countries supporting Ukraine, among them Poland, and regions bordering Ukraine would be especially vulnerable in the coming months. Other European leaders and intelligence services have shared his warnings that Russia is likely to step up its hybrid campaign.

In Dorohusk, people have lived in the shadow of the war for years. They watched Ukrainian refugees flee across the frontier in the early days of Russia’s 2022 invasion and, this July, had a Russian missile pass through airspace in eastern Poland before crashing some 90 kilometers (56 miles) inside the country.

But the recent drone attacks and the Polish government’s efforts to prepare the population for further serious incidents have brought a new sense of apprehension — and also confusion — among locals.

Jarosław Wójcicki, the Dorohusk school’s director, said staff, including the school psychologist, now discuss with students “practically every day” how to stay safe.

The school had to be evacuated once so far and Wójcicki showed the two rooms in the basement of the school building where the kids took cover. Windows had been boarded up to avoid glass shards hurting anyone in case of an explosion.

“The older children had no problem at all, without showing any particular emotion,” the director said. “You could see a little fear among the younger children, but they were well looked after by their teachers.”

Wójcicki is responsible for the safety of hundreds of children who travel from nearby villages to attend school in Dorohusk, and his voice wavered as he described the enormity of the task.

Poland’s Defense Minister Władysław Kosiniak-Kamysz visited the Dorohusk-Yahodyn border crossing on Sept. 22 and announced new air defense elements were being brought to the border region. He added that Patriot batteries were deployed in the two Polish regions bordering Ukraine, including the one where Dorohusk is located.

While the government’s warnings are stark, even communities closest to Ukraine are still catching up on civil defense preparedness.

“We are at the beginning of the process of building civil resilience and the resilience of the state to threats,” said Mirosław Sokal, head of resident safety for the city of Lublin, 90 km west of Dorohusk. “We have to remember that over the past 40 years we thought we would be living in peace.”

He said, given the lack of more solid infrastructure, Poles should respect one minimal rule when there’s an air threat: get inside and put two walls between them and any window.

Sawa, the Dorohusk mayor, said villagers typically live in individual homes with basements and that is the obvious place to hide in case of air threats. “If I don’t have a basement myself, my neighbor likely does,” he said.

But people on the streets of Dorohusk seemed more confused about their options in case of a real attack.

“For now, I sleep well at night, so I don’t really hear it,” said Irena Popek, a woman in her 80s. If planes are coming, she said, her basement was not an option as it was flooded. “I simply have nowhere to hide, and that’s it.”

Renata Pastuszo, a local shop employee, said she continued working through the recent siren alarm because it’s better to keep a positive spirit in front of the Russian threat.

Krzysztof Rulka, another resident, complained that alerts were now coming too often, leaving people confused about their meaning.

“If someone told me that a drone was going to explode in the center of Dorohusk, then I would know what to do,” he said. “But this kind of confusion — there’s an air attack somewhere in Ukraine — well, what am I supposed to do now? Run to Germany?”