Family members have joined the search for nearly two dozen people who were reported missing two weeks ago after a religious retreat in Venezuela, civil defense authorities said on Tuesday.

Between 16 and 20 people are believed to be missing, civil defense officer Yesnardo Canal told AFP, although local media reported there could be more.

An eight-day-old baby and other children are part of the group.

They went missing after leaving for what officials described as a religious retreat in the town of La Grita in western Tachira province on August 22, but officials have given no further details about the gathering.

More than 30 search and rescue specialists searched for the missing, aided by drones, sniffer dogs and local people from the mountainous area, officials said.

Family members have been brought in to join the search as they would be better able to identify loved ones, Canal said.