Three people have been confirmed dead after a four-storey building under construction collapsed Tuesday afternoon in eastern Rwanda.

About 80 people were reportedly putting final touches on the building in the district of Nyagatare, when it gave way at around 3:00 p.m. local time. Most of them are believed to be still trapped under the rubble.

According to Fred Sabiiti, mayor of the district, 26 people have been rescued from the rubble and rushed to a local hospital. Three victims who are critically injured have been airlifted to the East African country's capital Kigali for treatment.

"Police arrived at the scene shortly after the incident and embarked on an intensive rescue effort. We can hear cries of people trapped under the collapsed structure," Sabiiti told Xinhua in a telephone interview.

Up to 50 people are believed to be trapped under the debris, Sabiiti said.

"We are trying all the best to remove the victims although we can't tell the exact number of people still trapped," said the mayor of Nyagatare.

Ambulances and paramedics are on standby to treat and rush those rescued to various hospitals in Nyagatare and Kigali, according to the official.

By late at night, the official said, they will have got the exact number of people who were in the building and the possible cause of the collapse.

Efforts to reach the owner of the collapsed facility proved futile as his known number was off by press time.

In April 2012, one person died and four others were injured when a four-storey building, known as Petit Meridien collapsed opposite Hotel Umubano in Kigali.

City authorities blamed the owner of Petit Meridien for demolishing the building before seeking proper guidance from the authorities.