The new deal runs until 17 January, 2013.
The ex-Senegal international started his first game against Crystal Palace last weekend and he earned his side a point after heading home Blues' second goal in the entertaining 2-2 draw at St. Andrew's.
"I'm delighted that we have been able to extend Papa's deal into the New Year," said boss Lee Clark.
"I was absolutely delighted with his performance against Crystal Palace. He got stronger as the game went on and it was a typical goal of his. He’s a big fella and he attacks the ball with aggression. People think he’s just a big lad who intimidates the opposition but he’s a very good technician as well.
“Off the pitch he’s great to have around the place and the lads have taken to him really quickly."