Ernan and Phyllis Meenan had just left the capital when the bomb went off.
Mr.Meenan, who runs the Donegal Aid for Belarussian Children’s Project, is visiting an orphanage in the country.
The couple are also finalising plans to bring 50 children to Donegal for a month later this summer as part of a programme to improve their health.
Mr Meenan, from Ballybofey, said they were shaken by the attack but are determined to carry on their work and return to Ireland either on Friday or Saturday.
He told donegaldaily.com “We had just left the city and we got a real shock when we heard what had happened. We could so easily have been on that metro or in the station.
“But it won’t deter us from continuing with our work. The country is unstable at the moment but charities like ours need to continue our work for the sake of the children,” he said.
Mr Meenan said he and his wife will be returning to the capital to catch a flight but will make private travel arrangements and will not use public transport.
The couple have been welcoming Belarussian children and placing them with Donegal families for the past 18 years.
They also fund a hospice which provides palliative care in Mogilev.
“Today we have been handing out ice-cream to the children in a nearby orphanage and that is a real treat for them. Simple things mean so much to these children because they have so little,” added Mr.Meenan.
Monday’s bomb blast was aimed at the President of Belarus Alexander Lukaskenko.