French rescuers plucked three dozen migrants from the English Channel on Wednesday, bringing to 125 the number picked up since the weekend while trying to make their way to Britain, officials said.

The 36 migrants were on three separate boats that ran into trouble off the coast of Calais in northern France late Tuesday and called the coast guard for help, regional maritime authorities said in a statement.

They were rescued in three operations early Wednesday.

On Sunday, the interior ministers of France and Britain signed an agreement creating a joint police intelligence unit to combat migrant traffickers and reduce what they described as "unsustainable" numbers crossing the Channel illegally.

Last year, 2,758 migrants were rescued while trying to make the crossing, four times more than in 2018, according to French officials.

The coronavirus pandemic has reinforced the trend, with the reduced number of trucks going through the Channel Tunnel leading migrants to opt for small boats instead. 

Since the end of 2018, attempts by migrants from Africa, the Middle East and South Asia to make the dangerous crossing via the cold, choppy waters of the Channel have increased markedly, according to official data.

Rights groups have linked the increase to a police crackdown aimed at preventing the establishment of migrant camps near Calais, home to a busy ferry port and the Eurotunnel, and other areas along the French coast.

The attempts tend to multiply as the weather improves in summer.