Spain and Morocco Thursday agreed to open an "urgent" investigation into the first massive irruption of immigrants into the city of Ceuta, a Spanish enclave in Morocco.

Spanish Prime Minister Jose Luis Rodriguez Zapatero and his Moroccan counterpart, Driss Jettou, announced the investigation at the end of the 7th High-Level Bilateral Meeting in Sevilla, Spain.

At a joint press conference, the two leaders lamented the fatalities taking place in the early hours of Thursday, when 80 immigrants suddenly crossed over the fence separating the North African country from the Spanish autonomous city of Ceuta.

The "avalanche" of immigrants - the first of its kind - left at least five dead, according to Spanish Vice Prime Minister Maria Teresa Fernandez de la Vega.

For the moment the cause of the incursion is not known, but Spain is a country that remains attractive for many African immigrants who seek better opportunities.

Rodriguez Zapatero and Jettou said the results of the investigation on the irruption in Ceuta would be presented with the utmost transparency.

The investigation will clear up, among other aspects, the initial versions according to which some of the victims were killed by gunfire, either from the Moroccan or the Spanish side, although Ceuta prefectural sources later said two "sub-Saharans" died of lesions caused when crossing the fence.

The incident occurred a few days after some 1,500 immigrants crossed into Spain through the city of Melilla, another North African Spanish enclave near Ceuta, and forced the Spanish government to strengthen security with the presence of the army, local media said.

Rodriguez Zapatero said his government has not communicated any definitive information on the events and insisted that he will wait for the results of the investigation to inform of the incident "with rigor and transparency."

It is "premature" to present conclusions at present, he said in a statement at the end of the first session of the meeting, which will continue Friday in the Spanish cities of Seville and Cordoba.

Cooperation on illegal-immigration controls between Madrid and Rabat has improved this year. Despite the events of recent days, there has been a 40-percent reduction in attempts to reach Spain by sea or from Ceuta and Melilla.

Jettou said that since last week, Morocco has sent 1,000 more agents to the border with Ceuta and 600 to the Melilla border region.

Source: Xinhua