MEXICO CITY (Reuters) - The number of homicides in El Salvador slumped by 52.5 percent in the first four months of 2017 compared to the same period last year, officials said on Thursday, crediting new security measures in the violent Central American nation.

In the January-April period, 1,133 homicides were reported, compared to 2,387 in the same period in 2016, Security Minister Mauricio Ramírez said.

El Salvador, which saw a record number of homicides in 2015, put in place a raft of special measures in April, 2016 to combat gangs, called “maras”.

Speaking at a separate event, Attorney General Douglas Melendez said that gang members who have recently been deported from the United States have created new “cliques” named after U.S. cities and are sharing information with counterparts still in the United States.

The Salvadoran government on Wednesday proposed creating a registry of deportees from the United States who have a criminal record to prevent them from entering the maras.

Authorities also said that some Mara Salvatrucha (MS-13) members, who spilt from the gang due to a conflict over money management, created a new group called Mara Salvatrucha 503.

The Mara Salvatrucha, or MS-13 was formed in Los Angeles in the 1980s to protect early immigrants escaping civil war in El Salvador.

The gang, and its rival Barrio 18, have about 60,000 members together and are fighting each other for control of extortion, drug-trafficking and robbery in El Salvador.