The accident happened at a bus stop in the Ikeja area of Lagos, a city of around 20 million people, Lagos state emergency services said in a statement.
Sanwo-Olu tweeted Thursday that 85 passengers comprising state workers were aboard the bus.
“Lagos is in a state of mourning and for the next 3 days, I am suspending all campaign activities. All flags will be flown at half mast and tomorrow all civil servants will work till 12 noon before returning home to be with their loved ones during this trying time,” the governor further said in a series of tweets while calling for blood donations to treat the injured.
The country’s President Muhammadu Buhari described the accident as “distressing and extremely sad,” in a statement on Thursday.
“The accident at the level crossing involving a train and BRT staff bus is distressing and extremely sad. I pray for the souls of the deceased and quick recovery of the injured,” Buhari said while commending Lagos authorities for intervening swiftly at the scene of the collision.
Security guard Ubong Okon witnessed the aftermath of the crash, which happened from about 7 a.m. to 8 a.m. local time (0600 to 0700 GMT).
“I came out to open the gate, then I saw the train and the bus, I looked inside the bus, there were lots of passengers inside, I went inside and saw people with injuries, there was blood everywhere, then I started to help get people inside the bus out.”
Traffic jams are part of daily life in Lagos, where most people drive with little regard for road and safety rules.
In Africa’s most populous nation, many roads are poorly maintained and riven with potholes, leading to accidents that claim thousands of lives every year.
Aviation Minister Hadi Sirika said in a statement that he has directed Nigeria’s safety investigation agency to look into the cause of the accident.