Tension levels are increasing in the area patrolled by Irish peacekeepers in Chad.
Armed rebel groups are said to have crossed from Sudan into the territory controlled by 400 Irish troops.
However, according to the Defence Forces, Irish peacekeepers have had no sightings or any contact with the rebels.
Irish troops have evacuated around 50 humanitarian and 15 local security staff have refugee camps in Goz Amer, around 35km south of Camp Ciara - where the Irish peacekeepers are based.
The 99th Infantry Battalion says it has been actively patrolling and conducting surveillance operations in the area over the last number of days.
The rebels are reported to have clashed with Chad government forces in the southeastern Salamat region and are progressing towards the capital Ndjamena.
The Union of Resistance Forces rebels claimed a 'very short battle' took place yesterday near the border with Sudan and the Central African Republic.
There was no government confirmation of that battle, but the rebel incursion has raised alarm within the African Union.
In the statement, Hemchi said the rebels captured 12 army vehicles and destroyed nine others in yesterday's clash near the towns of Tissi and Haraz-Mangue.
There are no details of casualties on either side.
Chad's government later announced that the rebels had launched an assault backed by Sudan, using several hundred vehicles.
It accused Sudan of reneging on a weekend peace agreement, although Khartoum denied any part in the offensive.
The UN has urged its staff and the personnel of other non-governmental organisations to avoid leaving urban settlements and camps if possible.
A deal brokered by Qatar and Libya was signed on Sunday in Doha and is regarded as essential to any lasting settlement to a six-year-old uprising in the western Sudanese region of Darfur, where Chad's rebels have bases.
