Over the past three days more than 15,000 Nigerians have crossed the 300-metre (yard) river bridge that forms the border with Cameroon, following calls by military and local leaders for residents to return, an official in Gamboru said.
"More are coming in everyday," he added.
Boko Haram fighters seized Gamboru in violence-wracked Borno state in August 2014, forcing thousands to flee across the border to the town of Fotokol on the other bank of the river in northern Cameroon.
Chadian forces reclaimed Gamboru in February last year, after intense fighting that left hundreds of insurgents dead, as part of a regional military coalition put together to crush the Islamist group which has become a threat to regional security.
"We found a looted and burnt out town which is a shadow of its former self," said Abacha Mari, one of those who returned to Gamboru on Wednesday.
"More than nine-tenths of the buildings in the town have been damaged by fire while the rest have been washed away by the rains," he added.
"Everything was looted and the streets are barely recognisable."
- 'Nobody found anything ' -
Gamboru has been repeatedly targeted in the Boko Haram insurrection which has cost the lives of 17,000 people in Nigeria and made over 2.5 million homeless since 2009.
