LONDON - Nigeria has lifted a ban on 113 vessels into its territorial waters, a letter from the NNPC seen by Reuters on Thursday showed. The letter, dated September 8, said the president had approved the consideration of all incoming ships subject to a letter guaranteeing that they are free and will not be used for any illegal activity. It added that the president had directed a review of activities of all affected vessels to determine culpability in illegal operations in Nigerian territorial waters.