MEXICO CITY (Reuters) - In one week, 370 immigrant children, most of them from Central America, were found abandoned in Mexico, after traffickers promised to take them to the United States but left them to their own devices after being paid thousands of dollars, authorities said.

Almost half of them, 163 children under the age of 18, were found traveling alone, Mexico's National Migration Institute (INM) said in a statement.

Each month, thousands of immigrants, mostly from Honduras, Guatemala and El Salvador, attempt to emigrate to the United States, crossing several borders in the process, despite the threat from drug gangs that kidnap, murder and rape women.

The children told federal migration agents that their 'guides' abandoned them after accepting $3,000 to $5,000 in payments, INM said.

The children and young people, who came from three of the poorest countries in Central America, were found between March 17 and 24, in 14 different states in Mexico.

"The majority of the children showed signs of extreme fatigue, foot injuries, dehydration and disorientation whereby they didn't know where they had been abandoned," INM said.

Many immigrants are able to get to the U.S. and then entrust their children to the traffickers who pay large sums of money for them.

In the week the children were found, a total of 1,895 immigrants from various countries were detected in Mexico from countries as far away as Somalia, Japan and Syria, among others.

(Reporting by Anahi Rama; Writing by Christine Murray; editing by Gunna Dickson)