Aid agencies are trying to step up their work in Haiti, where a cholera outbreak is now known to have killed 1,344 people since last month.
Aid efforts, especially in the worst-hit areas in the north, were disrupted last week by protesters who blame UN peacekeepers for spreading the disease.
Officials said the security situation there had stabilised.
Campaigning is meanwhile in full swing for Sunday's elections despite some calls for a postponement.
Voters are due to elect a new president and members of the legislature.
Late on Friday, four candidates appealed for the election to be delayed so authorities could focus on tackling the cholera outbreak.
The four, none of whom is a front-runner in the 28 November poll, also called for an independent inquiry to establish the origin of the cholera.
Some Haitians have blamed UN peacekeepers from Nepal, where cholera is endemic, for bringing the disease to their country.
Violence erupted last week, with people setting up barricades and throwing rocks at UN vehicles.
UN agencies and other aid groups said the protests were preventing them from carrying out relief work in the Cap-Haitien area, which has the highest fatality rate in the country.
However, at the weekend, supplies were once again being sent to the area, humanitarian groups said.
"The security situation there has now stabilised," Imogen Wall of the UN humanitarian agency, Ocha, told Reuters.
"We're going to have to scramble to get back to where we were."
Oxfam said they planned to resume their work in the north on Monday.
In the capital, Port-au-Prince, one of the main challenges is to prevent cholera from spreading in the slums and tent camps housing more than one million people left homeless by January's devastating earthquake.
So far the squalid encampments appear to have been spared.
"In all the camps where we have been working since the earthquake, we have not had one single confirmed case of cholera," Raphael Mutiku from Oxfam told the French news agency AFP on Sunday.
"Most of the cases of cholera in Port-au-Prince are in slums that did not receive post-earthquake relief."
However, there are concerns that the peak of the disease has not yet been reached and that people's urgent needs are not being met.
Over the weekend, international medical charity MSF said the response so far had been "inadequate".
It said swift action was needed to build latrines, provide safe water supplies, remove bodies and reassure frightened people that the disease is treatable.
But the UN agencies have said that their work has been hindered by the recent riots.
UN officials have also said that the violence is being encouraged by forces that want to disrupt the presidential election.
Some 19 candidates are vying to succeed current president, Rene Preval and it is likely that the election will go to a second round run-off on 16 January.
Most candidates have insisted that the elections, which will also choose 99 deputies and 10 senators, should go ahead as planned.