An Egyptian border guard was killed on Wednesday during a shootout with human traffickers trying to cross into Israel with illegal African migrants, a security official said.

Thousands of Eritreans and Sudanese nationals flee each year to Israel with the help of armed groups across a vast desert region stretching from Sudan, through Egypt and up to the Sinai Peninsula.

The 22-year-old officer was stationed in the middle of the Sinai Peninsula when he was shot, officials said.

Israel’s population of African immigrants reached almost 54,000 in 2013, the majority of whom were Eritrean and Sudanese, the country’s immigration office said.

Last year, Israel constructed an electric fence along its 230-kilometer (143-mile) border with Egypt, attempting to put an end to illegal immigration.

In April 2013, Amnesty International said Eritrean refugees kidnapped in Sudan had been raped, beaten, chained and sometimes killed after being forcibly transported to Egypt’s Sinai Peninsula and held for ransom.