Unverified video footage showed the migrant caravan breaking the border fence and it is thought they were pushed back with pepper spray by the police. President Trump ordered for all road and pedestrian bridges to be closed, but now Pedestrian East and West are open both ways. San Ysidro is the largest land border crossings between the San Diego and Tijuana.
Groups of Central American migrants have been amassing in the Mexican border city over the last few day, drawing fiery rhetoric from the US President.
Over 7,000 migrants are thought to have gathered at the checkpoint.
The Mexican Interior Ministry has said it will deport hundreds of “illegal” migrants who tried to “violently” cross the border to the US.
They added the protest at the crossing has been contained and it will not require military forces.
Tear gas was fired by US border guards as migrants attempted to overwhelm border forces.
One video that emerged yesterday showed large numbers of migrants breaking through a border fence.
Another video captured in Mexico appears to show many members of the caravan crossing a canal towards the border.
Many of these people have travelled more than 2,500miles in the hope of reaching the US.
Trump, who ran for President on a ballot of stopping illegal immigration, has used explosive rhetoric about the migrants in Make America Great Again rallies.
He said on Twitter yesterday: “To those in the caravan, turnaround we are not letting people into the United States illegally.
“Go back to your country and if you want, apply for citizenship like millions of others are doing!”
Those trying to break through at the checkpoint were allegedly throwing projectiles at the the border forces.
The US Department of Homeland Security (DHS) said: “Migrants attempted to breach legacy fence infrastructure along the border and sought to harm Customs and Border Protection personnel by throwing projectiles at them.
“DHS will not tolerate this type of lawlessness.”
The migrants say they are fleeing persecution, poverty and violence in Honduras, Guatemala and El Salvador.
However, the US President has vowed to keep them all on the other side of the fence until unless a court decides to grant them asylum.