Luanda - All seven passengers and crew were killed when a plane bound for the Angolan capital Luanda crashed in a remote corner of the country, emergency services said on Friday.The Brazilian-built Embraer aircraft operated by Air Guicango crashed on Thursday after taking off from Dundo in the northeast near the Congolese border, said fire brigade chief Felismino Ndumba."The aircraft left Dundo at 16:58pm (1558 GMT) for Luanda. We lost contact shortly after take off," Ndumba told AFP by phone."Despite our efforts we haven't had any contact with the aircraft since then. There were seven people aboard including a Portuguese national and a South African."A government source told the Lisbon-based news agency Lusa that the Portuguese victim was a 39-year-old firefighter.The flight is thought to have crashed into a lake just south of Cuilo municipality, according to Ndumba. "It is impossible that there were any survivors," he said.The cause of the crash is still unknown but the fire chief said that the aircraft had recently suffered "malfunctions". Two military helicopters were dispatched to the region to locate the wreckage and the victims' bodies, according to air force spokesperson Francisco Waianga.Angola has a poor air safety record and all of the oil-rich African country's airlines are banned from operating within the European Union except for the flag-carrier TAAG.