A number of flyers were found on the ground in the city, which has long been hit by waves of clashes between Christian and Muslim ethnic groups that have left thousands dead.
The pamphlet signed by someone named Idris Musa and written in poor English listed some 21 targets in the planned attacks.
“We entire Muslim of Plateau State will never give up until we have our right … Nothing can stop us from bombing these areas before December 26 2011,” said the flyer seen by AFP.
Jos is the capital of Plateau state, located in central Nigeria.
A spokesperson for a military task force in Plateau said authorities were taking the threats seriously.
“There is a pamphlet in circulation threatening to attack some targets, including churches, private businesses and government institutions in Jos between now and December 26,” Charles Okeocha told AFP.
“As security agents, we are not taking the threat lightly. We have beefed up security to avoid any unpleasant situations.”
Jos lies in the middle-belt region between the predominantly Muslim north and the mainly Christian south of Africa’s most populous nation.
Dozens were killed last year on Christmas Eve in Jos in multiple bomb attacks claimed by the radical Islamist sect known as Boko Haram as well as in subsequent clashes.
Last weekend, three bomb blasts targeting bars as fans watched the Real Madrid-Barcelona football match on television rocked the city, with one death and 10 injuries reported.
Northern Nigeria has been hit by scores of attacks blamed on Boko Haram, which also claimed responsibility for the August suicide bombing of UN headquarters in the capital Abuja which killed 24 people .AFP