Islamabad , Pakistan ( CNN ) -- The death toll from a plane crash Sunday in Karachi , Pakistan , rose to 12 after an official confirmed the deaths of four people who were on the ground . The four laborers were sleeping in an under-construction building that the plane crashed into , said Pervez George , a spokesman for Pakistan 's Civil Aviation Authority . Additionally , a man on a motorcycle was critically injured when the plane crashed , George said . The plane crashed early Sunday in the southern port city , killing eight Russian nationals on board and sending flames shooting through the sky , a Pakistani official said . The cargo plane took off at 1:45 a.m. ( 3:45 p.m. Saturday ET ) from the Jinnah Karachi International Airport for Khartoum , Sudan , and went down a few minutes later in the Gulistan-e Johar section of Karachi , an area where many Pakistani naval officers live . The plane appeared to hit several buildings that were under construction . The pilot appeared to deliberately bring the plane down in a less densely populated residential area in order to save lives , . Masood Raza , a Karachi district government official , told CNN affiliate GEO News in Pakistan . `` If the plane would have crashed in a ( more crowded ) residential area , it would have been a very big disaster for the city of Karachi , '' Raza said . The Russian-made cargo plane was carrying relief supplies , including tents , to Africa before it went down . The plane arrived in Karachi on Saturday from Fujairah , United Arab Emirates , George said . A witness told CNN that he saw fire on one of the plane 's wings before it crashed . Firefighters , rescue personnel and area residents rushed to the scene , with jet fuel fanning the large flames and huge plumes of smoke . The blaze was put out by 4 a.m. , according to George , but rescue personnel continued to comb through the rubble looking for other people possibly killed or hurt . Bystander Mohammed Raees told GEO News that he was injured after flaming parts of a building hit him and the motorcyle he was preparing to ride . Hospital sources told the CNN affiliate that Raees had burns over 60 percent of his body .
Four workers on the ground were killed in the crash . The pilot probably saved lives by guiding the plane to a less crowded area , an official says . Comment: All 8 killed onboard were Russian crew members of the Sudan-bound aircraft .