By Drazen Jorgic

MEXICO CITY (Reuters) - Mexican President Andres Manuel Lopez Obrador said on Wednesday that clashes between migrants and members of the National Guard on the border with Guatemala this week were an "isolated case" and that security forces are instructed to not use violence.

The influx of U.S.-bound Central American migrants seeking to pass through Mexico has posed a major headache for Lopez Obrador amid fierce pressure from the administration of U.S. President Donald Trump to prevent the asylum seekers from reaching the U.S. border.

Mexican security forces on Monday fired tear gas at groups of rock-hurling Central American migrants who waded across a river into Mexico earlier in a chaotic scramble that saw mothers separated from their young children.

About 1,000 mostly Honduran migrants managed to cross the border with Guatemala into Mexico, but several hundred have been immediately deported on planes and buses, Mexican officials said on Tuesday.

Lopez Obrador, blaming the organizers of the migrant caravan for the scuffles earlier in the week, said "there are instructions that force is not used" by Mexico's National Guard militarized police.

"We want peace, we want to resolve disagreements with dialogue," Lopez Obrador said during his regular morning government news conference.

Some of the Hondurans in the migrant caravan were returning to their homeland voluntarily, Lopez Obrador added.

Mexico's tougher approach to migrants and increased policing of its southern border following U.S. threats to impose tariffs has led to a sharp drop in the number of Central Americans seeking asylum at the United States' southern border.

(Reporting by Drazen Jorgic and Noe Torres; Editing by Dave Graham, Andrew Heavens and Andrea Ricci)