Nigerians have continued their protests for a fourth day against the government's cancelation of a fuel subsidy, while the U.N.'s human rights chief called on the government to avoid using excessive force in responding to the demonstrations.

Protesters gathered in multiple cities Thursday, including the commercial capital of Lagos, as businesses and banks remained closed.

U.N. High Commissioner for Human Rights Navi Pillay said in a statement Thursday that authorities need to “earn the respect and support” of the public by respecting human rights. She also expressed concern about recent deaths during the protests and called on Nigeria to carry out a full investigation.

Ending the fuel subsidy has doubled the cost of gasoline since New Year's Day, and labor unions have called for an indefinite strike.

Most Nigerians live on less than $2 a day and the fuel subsidy was one of the few benefits they received from the country's oil wealth. Some economists called the subsidy corrupt and wasteful, saying it encouraged smuggling into neighboring countries where fuel was more expensive.

A Nigerian oil workers union said Wednesday it is taking the first steps to shutting down production. A shutdown could devastate Nigeria's economy and even the threat of one may affect global oil prices.

Nigeria is Africa's top oil producer and exports more than 2 million barrels of crude a day.

President Goodluck Jonathan is refusing to reinstate the subsidy, saying the government can no longer afford it.