Dozens of migrants, including Palestinians, were arrested near Poland as the Central European country is increasing the number of troops on its border with Belarus to around 10,000 to stem a surge in migration which it blames on Minsk, its defence minister said on Monday.

Hundreds of people from places like Iraq, Afghanistan and Africa have been trying to cross the border illegally every day, and Poland has beefed up security in the region, brushing aside criticism that it is treating the migrants inhumanely.

Over the weekend, groups of about 60 or 70 migrants, including Palestinian refugees, had twice attempted to force their way through the border before they were caught by border guards.

The European Commission and Warsaw say the flow of migrants has been orchestrated by Belarus in a bid to put pressure on the European Union over sanctions it imposed on Minsk. Belarus has denied this.

Poland has declared a state of emergency in the region and plans to build a wall on the border.

The Polish parliament has also passed legislation that human rights advocates say aims to legalise pushbacks of migrants across its borders in breach of the country’s commitments under international law.

Polish divers on Wednesday afternoon found the dead body of a 19-year-old man from in the river Bug at the Belarus border, as the number of deaths at the Polish-Belarusian frontier climbs to eight.

“The identity was confirmed by the second young man with whom he tried to illegally cross the Bug the day before. Documents were also found next to the body. He is, beyond doubt, a 19-year-old citizen of Syria,” a spokesperson of the provincial police told the Polish state news agency PAP.

The teenager was reported missing on Tuesday morning as he tried to cross the river. Polish forces will now investigate his death, PAP reported.

Polish border guards said they rescued another Syrian man, who told them he and another migrant were pushed into the river by Belarusian police forces on Tuesday.

The death of the 19-year-old Syrian national is the eighth at the border between Poland and Belarus since this summer. Last week, the body of a 24-year-old Syrian man was spotted from a helicopter lying dead in a field, the Guardian reported.