A magnitude 6.2 earthquake struck about 219km west-northwest of Pangai, Tonga, on Thursday, the United States Geological Survey (USGS) said.
The earthquake was at a depth of 14.5km, the USGS said.
There has been no tsunami warning issued by either the Tongan or Fijian authorities, with Pangai being close to Fiji's Lau Group.
A team of Tongan geologists is expected to head out first thing in the morning to the north of the country to assess if there is any damage caused by Thursday night's earthquake.
Tonga's lead geologist Ta'aniela Kula said they had not been able to reach their teams by satellite phone on nearby Ha'apai Island.
Kula, who is on the main island, Tongatapu, said they did not feel anything.
"There's disconnection which is why we can't get a hold of our colleagues on Ha'apai. Nothing was felt in Tongatapu.
"We are expecting a boat to arrive from Ha'apai in the morning and we'll be able to head out to the area and assess the situation better.
"The earthquake was likely located [between] Tonga and Lau. A 6.2 [magnitude] quake is not expected to do much damage but you can never know."
Fiji Meteorological Service said they had not received a warning from the Pacific Tsunami Centre in Hawaii.
New Zealand's Civil Defence Emergency Management had also not received an alert on their radar.
- RNZ / Reuters