The Boeing 737, which was en route to the capital, Abuja, lost contact with the control tower five minutes after taking off from the international airport in Lagos at 8:45 p.m. on Saturday, said Jide Ibinola, a spokesman for the Federal Airport Authority of Nigeria.
The flight is popular among Nigerians and expatriates shuttling between the two cities.
Abilola Oloko, a spokesman for Oyo state where the plane crashed Saturday after leaving Lagos, initially said that more than half of those on board had survived and urged "all medical personnel" to rush to the scene. But he later asserted that "the latest reports coming to us say that all the people on the plane died."
He blamed confusion at the crash scene for the conflicting reports.
Search teams located the downed aircraft, operated by Nigerian-run Bellview Airlines, near the town of Kishi, 120 miles north of Lagos, police Spokesman Bode Ojajuni said.
President Olusegun Obasanjo — grieving for his wife, Stella, who died early Sunday in Spain — was personally overseeing search and rescue operations and asked "all Nigerians to pray for all those aboard the plane and their families," his office said in a statement.
Representatives of many countries gathered at the airport to find out if any of their citizens were on board the flight.
The airline said 117 people were on board — 111 passengers and six crew members — but gave no more details.
Ibinola said the craft was headed to Abuja, on what was supposed to have been a 50-minute flight. There was no immediate indication the crash was terrorism-related.
Officials said earlier that the military had mounted a nighttime helicopter search off the west African coast as state television reported that pilots issued a distress call before the plane disappeared from radar about 15 miles west of Lagos over the Atlantic Ocean. It was not clear why the wreckage was found inland.
Bellview, one of about a dozen local airlines, is a privately owned Nigerian company that operates a fleet of mostly Boeing 737s on internal routes and throughout West Africa. Bellview first began flying about 10 years ago and has not suffered a crash before.
Many consider Bellview to be among the most-reliable airlines shuttling between Nigeria's often-chaotic regional airports, which can resemble bus depots where crowds battle for seats on planes.
In May 2002, an EAS Airlines jet — another domestic carrier — plowed into a heavily populated neighborhood after takeoff at the airport outside the northern city of Kano, killing 154 people in the plane and on the ground.