Nigerian authorities say the death toll from Sunday's plane crash in Lagos is up to a least 157, after officials confirmed the deaths of at least four people on the ground.

Workers have recovered at least 137 bodies from the crash site but torrential rain and strong winds slowed recovery efforts on Tuesday.

The Dana Airlines plane was traveling from Abuja to Lagos when it plowed into a residential neighborhood. The pilot reported engine trouble shortly before the crash.

All 153 passengers and crew members were killed along with an unknown number of people on the ground.

Emergency officials say search crews have recovered the plane's flight data recorder and its cockpit voice recorder, which may shed light on the cause of the crash.

Ibrahim Mamman, a pilot with the privately owned IRS airlines in Nigeria, tells VOA that aircraft maintenance has been an ongoing issue.

“The issue there is the engineers need to be trained. They need training and training and training — training all the time.”

Nigerian President Goodluck Jonathan has declared three days of official mourning. He visited the crash site on Monday and promised that such a calamity will never happen again, pledging to improve air safety.

Dana Airlines is a domestic air carrier that operates a fleet of Boeing MD-83 aircraft for the hour-long flight from Abuja to Lagos.

Aviation officials say an undetermined number of foreigners were on the flight, including Chinese nationals, some U.S. citizens and at least one French citizen.