Egyptian authorities have arrested 33 African migrants, including four children, who were trying to cross the border illegally into Israel, a security official said on Wednesday.

"The group, which included four children aged three to eight, was arrested on Tuesday evening in central Sinai near the border with Israel," the official told AFP.

The porous 250-kilometre (155-mile) Egypt-Israel border has become a major transit route for migrants, asylum-seekers and drug smugglers.

So far this year, 20 migrants have been killed attempting the crossing and 641 have been arrested, according to an AFP count.

In a report published last week, Amnesty International urged the Egyptian government to launch an investigation into the shooting dead by police of people crossing the border illegally.