Lagos - A top Nigerian official was scheduled to meet the Turkish ambassador on Friday after hundreds of rifles allegedly from Turkey made it to the west African country this week falsely labelled as plumbing materials.It was the fourth time this year Nigerian customs officers had intercepted illegal arms shipments from Turkey at the nation's ports, a customs official said.According to the Nigeria Customs Service, a total of 2 671 action pump rifles allegedly imported from Turkey have been seized in Lagos since January. "The government is worried about the incessant importation of arms from Turkey. This year alone, four shipments have come from that country," customs spokesperson Joseph Attah told AFP. "Colonel Hameed Ali, the comptroller-general, will be meeting with the Turkish Ambassador in Abuja today (Friday) to address the issue." Attah said 470 rifles, which had been falsely declared as elbow joints for plumbing, were intercepted at the port on Tuesday.That shipment was uncovered barely a week after a 20-foot container-load of 1 100 pump-action rifles was impounded at the same port. "We have found out that the people bringing in these weapons are Nigerians. They have syndicates in Turkey who are manifesting these weapons," Attah said. A local oil firm involved in the shipments is under investigation. "We are yet to get to the bottom of the whole issue. We will investigate to know if these weapons are meant for commercial purposes or group of insurgents or agitators," said Attah.The Turkish embassy was not immediately available for comments. Nigeria is facing a string of security challenges, from Boko Haram's Islamist insurgency in the northeast to militants targeting oil and gas facilities in the south.In between, there is growing conflict between largely nomadic herders and farmers. There has also been unrest linked to separatist sentiment in the southeast.