A number of homes were evacuated after the device was thrown at a property in the New Lodge area.
Councillor Nuala McAllister said: “Those behind this terrifying attack don’t speak for the whole community. I’ve spoken to a number of residents who are extremely concerned about what has happened.
“While we are extremely lucky this incident did not lead to serious injury or even death, it would have been terrifying for those living in the property and my thoughts are with them.
“The thugs who orchestrated this attack have not only caused serious disruption to the lives of many, but have brought fear back into the community – reminding everyone of the past we all want to leave behind.
“There is no justification for those responsible for this terrifying incident and I would urge anyone with information to contact the PSNI as soon as possible so they are unable to strike again.”