CAIRO, (Reuters) – Egypt arrested 82 African migrants heading for the Sinai Peninsula where they hoped to slip across the border to Israel, security sources said on Wednesday.

The migrants, who included Ethiopians and Eritreans, were hiding in a cave near Suez city early on Wednesday, one of the sources said.

“They said they were waiting for a bus to take them to Sinai from where they would go to Israel to search for jobs,” the source added.

It was the biggest such round-up reported in the area since 2009 and comes as Israel builds a 140 km (88 mile) barrier and surveillance system along part of its border with Egypt’s Sinai desert, where many migrants enter the Jewish state.

Many of the migrants are fleeing conflict or poverty.

Groups detained in the area tended to number around 10 until this year, when numbers increased – some 50 were arrested in one group last month. Egypt has come under pressure from Israel to allow fewer to cross the border.

Rights groups have criticised Egyptian border police for shooting dead many of the migrants, who are mostly unarmed. Police have shot dead at least 30 this year, up from 19 in 2009.

Egyptian security forces say they fire at migrants only after repeated orders to stop are ignored