UN envoy Jens Anders Toyberg Frandzen and diplomats watching events in the West African nation, still rebuilding from a devastating 1991-2002 civil war, called on the government to take action to ease the political temperature ahead of the November 17 votes.
President Ernest Koroma of the All People's Congress (APC) is seeking a second term in the election. The main competition comes from the Sierra Leone People's Party candidate Julius Maada Bio.
"As the elections draw closer, the intensity of political competition, in particular between the two major political parties, the APC and the SLPP, is expected to increase and tensions are expected to rise," Toyberg Frandzen told the UN Security Council.
He added that no political violence has been reported in recent months, but said "recent incidents involving the use of force by the police in response to disturbances and other situations in various parts of the country have caused concern."
The UN envoy welcomed a government inquiry into events which "led to the use of lethal force." He stressed "the need to ensure respect of rule of law and professional conduct by all during the electoral period" but also expressed confidence that the tensions could be managed.
Guillermo Rishchynski, Canada's UN ambassador and head of a UN peacebuilding commission for Sierra Leone, said the elections would be an "important moment" for the country which saw 120,000 dead and tens of thousands mutilated in the civil war.
The elections "represent a crucial test and are widely viewed as a core benchmark for peace consolidation," Rishchynski told the Security Council.
He added that in visits to Sierra Leone, groups have "raised concerns about persistent tensions between the major political parties, the role of unprofessional media willing to exacerbate political divides, and the risk that irresponsible actors will encourage youth to engage in politically motivated violence."
Sierra Leone's UN ambassador Shekou Touray said President Koroma was in talks with all sides "on the attainment of collective commitment to peaceful, free, fair, transparent and credible elections."