Vanuatu's National Disaster Management Office Director Shadrack Welegtabit said there were no initial reports of damage or injuries but he was still awaiting information from some of the outer islands closer to the epi-centre.
Port-Olry is located on the island of Espiritu Santo, in the Sanma Province of Vanuatu.
A hotel owner on the island told Al Jazeera that the earthquake was "a big one" but that the shaking lasted only a few seconds.
"A few broken glasses, but no one hurt as far as I know."
Tarcisius Alguet from the Little Paradise Bungalows in Port Olry, however, told the Qatari-owned broadcaster that the earthquake felt like it lasted for roughly three minutes.
"First there was noise, and then the trees started to shake," Alguet was quoted by Al Jazeera as saying. "Then, the ground started to move slowly."
He was not aware of any damage to buildings in Port-Olry, however.
Al Jazeera also reported that a resident in Port Vila had felt the quake, but there was no visible damage in the capital.
Vanuatu sits on the Ring of Fire, the arc of seismic faults around the Pacific Ocean where earthquakes are common.
Port-Vila was devastated by Cyclone Pam earlier this year.
In March, the category 5 cyclone tore through the Pacific Island nation, severely damaging the capital and surrounding villages.
