A spokeswoman for the United Nations refugee agency in Uganda says hundreds of Congolese are fleeing into Uganda to avoid being forcibly conscripted into the ranks of the rebel group M23.

Lucy Beck of UNHCR said Wednesday that more than 250 Congolese villagers crossed into Uganda on Tuesday alone, joining at least 1,000 more who fled in recent days.

She said the situation is "uncertain," with the agency stocking up on supplies in anticipation of more arrivals.

M23, the most prominent rebel group in eastern Congo, has been talking up its readiness to defend itself against an offensive brigade of U.N. peacekeepers set to be deployed there. According to Beck, the refugees are "fleeing M23 preparations."

Peace talks between the rebels and the Congolese government have hit a dead end.