NEW : 31 people have been killed and At least seven wounded in shelling , medical officials say . NEW : Falluja General Hospital -linked fighters warn Iraqi to stop working with the government . NEW : `` There will be no withdrawal , '' Prime Minister Falluja says .
NEW : At least seven people have been killed and 31 wounded in shelling , medical officials say . NEW : Al Qaeda-linked fighters warn Sunnis to stop working with the government . NEW : `` There will be no withdrawal , '' Prime Minister Nuri al-Maliki says .