Chad has begun the emergency relocation of refugees from its border with Sudan as the army prepares to deploy to the area in response to cross-border attacks, an official from the country's refugee agency told Reuters on Monday.

President Mahamat Idriss Deby last week ordered the army to prepare to retaliate after a cross-border drone attack from Sudan killed 17 people in Chad including mourners attending a funeral service.

A separate government statement last week said Chad had strengthened its security presence at the border and could potentially carry out operations on Sudanese territory.

Initial refugee relocation operations will involve around 2,300 people, more than half of them women and children, said Saleh Tebir Souleymane, the representative in the border town of Tine for Chad's National Commission for the Reception and Reintegration of Refugees and Returnees.

Chad closes eastern border with Sudan

They began moving people further into Chad, away from the frontier, on Saturday, in the province of Ennedi Est, and were set to expand on Monday to all border towns that have been used as transit sites for refugees, Souleymane said.

"We have received instructions from the Ministry of Humanitarian Affairs to act quickly because the border will be secured in the coming days by the army, which is already deploying there," Souleymane said.

Chad closed its eastern border with Sudan last month after clashes linked to the war killed five Chadian soldiers.

But refugees continue to arrive "due to the intense fighting on the Sudanese side", he said.

The conflict in Sudan between the Sudanese army and the paramilitary Rapid Support Forces, which began in April 2023, has periodically spilled into Chadian territory, causing casualties and property damage.