Foreign Minister Gabrielius Landsbergis said on Tuesday that Lithuania has requested that the European Union penalize Belarusian people and firms for allegedly assisting migrants in crossing into EU member states.

Lithuania, Poland, and Latvia, all EU member nations, have reported an upsurge in the number of migrants attempting to enter their borders from Belarus, many of them are from Iraq and Afghanistan.

After the EU imposed sanctions following a disputed presidential election last year and his ensuing crackdown on protestors and dissidents, Belarusian President Alexander Lukashenko announced he will no longer detain migrants.

“We must send a very clear signal not only to Belarus but to every dictator who would use such instrument against the European Union or any of its members, that not only he fails, but he also gets a strike back,” Landsbergis told a news conference in the border town of Medininkai.

“Sanctions are one such answer.”

He said his government had presented the EU’s External Action Service with a list of Belarusian citizens and companies it holds responsible for the increased migrant arrivals.

Austrian Foreign Minister Alexander Schallenberg agreed, telling the same news conference: “Those responsible must face strict sanctions.”

The Lithuanian Government said on Monday it will finish building a 508 km (315 mile) razor-wire-topped fence on its border with Belarus by September 2022, at a cost of up to 152 million euros.

Officials from Poland and Latvia later advocated the construction of similar fences along their own borders with the former Soviet republic.

The EU says Belarusian President Alexander Lukashenko is waging “hybrid warfare” with migrants to exert pressure on the bloc.