Hundreds of diamond smugglers are pouring into Angola's eastern diamond region of the Lundas every day from the Democratic Republic of Congo, a top Angolan general said on Monday, Reuters reported.

The general, who asked to remain anonymous because of the military's secrecy laws, said Angola had recently invested $13 million to increase military patrols along the Congo border and stop the flow of illegal immigrants from as far away as Senegal, the report said.

"We're talking about hundreds of men, women - even pregnant women - who try to break through Angola's border every day," he said. "The Angolan government is increasing military personnel along the border with the Democratic Republic of Congo to stop the flow of diamond smugglers."

Although strong regional allies, the neighbors have been at odds over their 2,000 km (1,250 mile) land border. Congo has repeatedly accused Angolan troops of trespassing onto its territory, said the report.

Angola has said troop incursions into Congo were aimed at controlling the flow of illegal immigrants into the south-western African nation, it said.

Mining Minister Makenda Ambroise, who has admitted to the presence of illegal diamond smugglers from the Congo in Angola, declined to comment. "I don't want to talk about diamond smugglers," he told Reuters.

Angola, which emerged from an almost three-decade long civil war in 2002 to become the world's fifth biggest diamond producer, allows only companies that partner with state-run firm Endiama to explore for diamonds.

The country's immigration office announced last week that over 62,000 illegal immigrants had been deported from Angola's eastern diamond provinces of Malange, the Lundas and Moxico, but did not specify whether they were diamond smugglers.