The attack occurred on Sunday night (17 September) and resulted in residents being evacuated from their homes.
Ms Nicholl has said: “This attack, the fourth in just two weeks, must be robustly condemned by all political parties. The behaviour exhibited here is totally unacceptable and represents only the very worst aspects of our society.
“It does not represent the community or people of South Belfast, who overwhelmingly stand in solidarity with the victims and embrace and celebrate the diversity of our city.
“The repeated hate-fuelled attacks we’re witnessing are deeply unsettling for minority ethnic communities both in Belfast, and right across Northern Ireland. People deserve to live free from the threat of violence and free from fear of attack. Businesses on the Donegall Road also cannot operate within this type of environment and they need assurances that an attack of this nature will not happen again.
“It is time for all political representatives to step up and condemn this, and call for an end to this string of attacks against our minority ethnic communities. However, condemnation alone is not enough. What we need to see is political parties of all persuasions providing leadership and taking sustained action to engage on these issues and support all those who call Belfast home.
“However, police action is required to bring the perpetrators of these heinous crimes to justice. I would urge anyone with information, who may have witnessed the attack or captured dashcam or mobile phone footage of the fire, to contact the PSNI on 101 or report it anonymously via Crimestoppers.”