The International Organization for Migration and the UN refugee agency said Tuesday they are "very alarmed" by reports about the treatment of migrants at the Belarus-Poland border.

- It's a situation for which we've been expressing our concern for quite some time - UNHCR spokeswoman Shabia Mantoo said at a UN news conference in Geneva.

The two organizations referred to reports surfacing on Nov. 8 of a large group of migrants and refugees, among them women and children, on the Belarusian side of the border.

They were moving towards the international border crossing point "Bruzgi," with Poland.

They had allegedly settled in a makeshift camp near the border during the night.

- Taking advantage of the despair and vulnerability of migrants and refugees by offering them unrealistic and misleading promises is unacceptable and has severe human consequences - the IOM and UNHCR said.

Tensions between Poland and Belarus escalated on Monday after nearly 4,000 migrants, mainly from the Middle Eastern countries, headed to the Polish border and tried to breach the barriers, the UN noted.

Polish border guards, police, and soldiers used tear gas on migrants who tried to break through the barbed-wire fences.

The UN groups have contacted both governments and are seeking an urgent resolution as well as immediate and unhindered access to the group.

They want to ensure that humanitarian assistance is provided, there is identification and protection of those in need, and that those who wish to apply for asylum can do so where they are.

Several deaths were recorded in the border area in recent weeks, the further loss of life must be prevented, and the humane treatment of migrants and refugees ensured, said the agencies.

The EU accuses the Belarusian administration of "using irregular migration as a tool" and "trying to destabilize the EU" by sending migrants to the borders of EU countries -- Poland, Lithuania, and Latvia.