RABAT, June 17 (Xinhua) -- An increasing number of African migrants are trying to reach Europe via Morocco, while number of migrants who choose the Libyan-Italian route declined.

On Friday, 307 people were rescued in the Strait of Gibraltar, while the bodies of four dead were recovered. This number adds up to some 1,153 migrants arriving at Spain's southern shores in the first 10 days of June, according to the International Organization for Migration (IOM).

On the Moroccan side, security forces arrested some 57 migrants as they were embarking on a boat in route to Europe Friday, and arrested 155 others on Saturday for attempt to organize an illegal migration operation.

These figures reflect a returning focus of migration attempts via Morocco to Spain after years of surge in the Libyan-Italian route.

According to IOM, more than 9,315 reached Spain by sea from January to June 10 compared to only 4,161 migrants during the first half of 2017, and 8,100 during the whole year of 2016.

A vast majority of these migrants are likely to have arrived from Morocco as distance between Spain and Morocco is shorter compared with other North African countries.

Meanwhile, the number of migrants arriving in Italy, typically from the more favored Libyan route, has drastically declined. A total of 14,330 migrants reached Italy between January and June 2018, down from 61,799 migrants during the same period last year.

However, passing through Morocco and avoiding war-wracked Libya is perilous, too. At least 244 people have died at sea so far this year trying to cross to Spain, an increase of more than 400 percent year on year, IOM statistics show.

The shifting of the routes is partly because of the stricter counter-migration measures in Libya and Italy, the humiliating conditions the migrants are experiencing in Libya and the growing number of African migrants arriving in Morocco.

Thousands of sub-Saharan African migrants try to flee poverty and unrest in their countries via Morocco to Europe every year, either by land into Ceuta and Melilla, two Spanish ports in the Moroccan territory, or by sea to Spain, often in flimsy vessels.

According to Morocco's Interior Ministry, security forces arrested some 50,000 illegal migrants in 2017 and dismantled over 70 organized illegal migration networks.

In addition to the security approach, Morocco has adopted since 2014 more open migration policy, opening windows to migrants to earn legal status in the country.

The North African kingdom organized two operations to regularize the status of these migrants in 2014 and 2016. In the first operation, over 23,000 have been granted a legal status, most of the from sub-Saharan Africa.

In the second operation, which ended last December, the Moroccan authorities received some 28,400 requests.