GUATEMALA CITY (Reuters) - Guatemala's migration institute said on Tuesday it found two boats transporting 50 Cuban migrants and two Honduran migrants trying to reach the United States illegally by sea.

       The boats were discovered on Monday night by the National Defense Navy in the area of ？？Rio Dulce, a lake and river system on Guatemala's eastern coast, according to a statement by the institute released on Tuesday. Another eight Cuban migrants, part of the same group, were detained while traveling in the area by land.

       The immigration authority called the attempted maritime passage "a new trend in the region" in its statement.

       The migrants were expelled to Honduras, where they had set out from, the authority said.

       Cuban nationals must present a visa to enter Guatemala. Colombia, Costa Rica and Panama now also require a visa to pass through their airports, frustrating waves of Cubans looking to flee the Caribbean country as its economy falters.

       According to migration data, 84 Cubans have been expelled so far this year and last year after trying to cross through Guatemala, part of the route to reach the United States.

       The number of Cubans detained at the border between the United States and Mexico also sky-rocketed in February, reaching to 16,531, the highest monthly figure on record, according to U.S. Customs and Border Protection data.

       (Reporting by Sofia Menchu, writing by Cassandra Garrison; Editing by Marguerita Choy)