Spain has strengthened its security forces at its North African Melilla border after hundreds of people recently stormed the perimeter in one go.
The latest wave of immigrants was the biggest group of people trying to get into Spain over recent years.
On Tuesday and Wednesday Madrid sent 100 more police officers, raising the total at the point to 150, a source at the Interior Ministry said.
They also plan to reinforce the rapid response unit, increasing it by 20 more personnel, bringing the total to 80.
Immigrants from all over Africa – from countries such as Mali, Togo and the Ivory Coast – regularly attempt to cross the razor-wire fences of the Spanish exclaves Ceuta and Melilla, which are surrounded by Moroccan territory and sea.
The numbers of people searching for a better life in Europe via the land borders have multiplied as increased naval patrols discourage attempts to get to Europe by boat.
Reportedly, just over 1,000 people breached the 12-kilometre-long fences around Melilla in the whole of 2013.
This year has already seen a rise though, as more than 1,600 have broken through the border since the beginning of 2014.
Once they have reached Melilla or Ceuta the immigrants are fed and given clothes and somewhere to sleep in specially-equipped centres. It is here that the individuals are processed.
These centres are hugely overburdened at the moment though, with more than double the capacity being housed there.
Many of the individuals end up in continental Spain and either stay in the country or move on to other places in Europe.
Last month, the EU asked Spain to explain why police had fired rubber bullets when a group of African migrants tried to swim to Ceuta. Fifteen of the group drowned.
The problem is ongoing and, at the moment, there is no solution in sight.