JOHANNESBURG, Dec. 9 -- The South African civil aviation system on Monday announced that they are ready to serve Mandela mourning activities.

"Measures have been put in place to ensure safe air travel," said Air Traffic and Navigation Services (ATNS) spokesperson Percy Morokane.

After the 95-year-old anti-apartheid icon Nelson Mandela passed away on Thursday evening, mourning people have been streaming to remember him.

The South African government on Monday said more than 90 heads of state and government will attend the historic national memorial service of Mandela, which will be held in Johannesburg in the eastern province of Gauteng on Tuesday.

Mandela's funeral will be held at his home village in the southern province of the Eastern Cape on Dec. 15.

As part of the new measures,"an airspace management unit has been set up to co-ordinate slots and air traffic flow management from various airports," said Morokane.

The ATNS is the sole air traffic and navigation services provider in South Africa, operating at 22 airfields around the country.

"The potential risks that include adverse weather conditions have been identified ...diversion alternatives have been identified, and will be reviewed on a 24-hourly basis," the ATNS spokesperson said,

To ensure the plan will be implemented smoothly, the ATNS staff have been sent to the designated airports across the country to provide the day and night air traffic management services.

The Airports Company South Africa (ACSA) also said on Monday that it was implementing a new plan to help the movement of passengers and aircraft since Mandela passed away.

As a public company, the ACSA operates nine major airports in the country, including the international airports in the country's largest city of Johannesburg, the second largest city of Cape Town and the southeastern port city of Durban.

"The normal major event processes have been activated at the international airport in Johannesburg," said the ACSA in a statement.

The ACSA pledged it could serve the mourners with dignity and professionalism in the coming days.