Migrants raised a white flag at the fenced-off Bruzgi-Kuznica border crossing after Polish border guards used water cannons and tear gas against them on Tuesday.

Migrant children stood near the barbed wire fence, addressing Polish border guards in English: "Please help! Open the door".

Some migrants raised a white flag and a placard asking, "Where is human rights?"

A cameraman of Belarusian TV channel ONT is also captured on the video after allegedly getting injured when Polish border guards tried to disperse migrants using tear gas and water cannons.

Polish special services estimate that around 3,500 migrants have gathered at the Bruzgi-Kuznica border crossing.

Warsaw has increased the number of troops on the border to repel the migrants and also brought in special equipment.

Belarusian President Alexander Lukashenko said on Monday that Minsk was ready to organise flights to send migrants back to their homeland.

The migrant crisis comes amid escalating tensions between the EU and Belarus. Brussels has accused Lukashenko of orchestrating the migrant flow as part of a 'hybrid war' designed to put pressure on the bloc over sanctions. Minsk has denied the allegations.

Poland last month strengthened border patrols on the frontier with Belarus and put up a barbed-wire fence in place in an attempt to stem the flow.