Reports of a thousands-strong caravan have been in the headlines for weeks, but with one week until the midterm elections, a second caravan of immigrants has formed and penetrated into Mexico.

The second caravan, estimating as high as 3,000, clashed with Mexican officials at the border, and they appear to be adopting more violent tactics than the first caravan that made headlines over the past two weeks.

The standoff on the riverbank follow a more violent confrontation that occurred on the nearby bridge over the river the night before, when migrants tossed rocks and used sticks against Mexico police. One migrant was killed Sunday night by a head wound, but the cause was unclear.

While migrants on the bridge had appeared to be preparing for a second day of confrontations early Monday, instead they tried the route taken by the first caravan 10 days ago after it, too, was blocked: turn to the river below.

The first, larger caravan made it across the river by wading or on rafts, and now is advancing through southern Mexico.

But since that crossing, the Mexican Navy has begun patrolling the Suchiate River and Mexican police have taken up positions on the riverbank, insisting migrants register before entering and show travel documents that many do not have.

News of the second caravan comes as President Donald Trump dispatches more than 5,000 support troops to the southern border in an effort to block the first caravan from entering the United States.

It is the tactics of the second caravan that are more troubling. Media reports indicate that the use of gasoline bombs in soda bottles, as well as PVC tubes used to launch projectiles at Mexican police. If the second caravan is more violent than the first and it reaches the southern U.S. border, a clash with the military seems inevitable.