Mogadishu - At least 90 people - including students - have been killed after a car bomb exploded at a busy security checkpoint in Somalia on Saturday.

The morning blast in the capital, Mogadishu, targeted a tax collection centre during rush hour, said Captain Mohamed Hussein. The dead included many students and two Turkish nationals, the Somali foreign minister said.

A large black plume of smoke rose above the city in what was one of the deadliest attacks in Mogadishu in recent memory, reported the Associated Press.

In an update, Reuters says an international organisation - which didn’t want to be named - confirmed that more than 90 victims have so far died as a result of the explosion. A Somali MP also tweeted that the death toll had spiralled to more than 90, including 17 cops. Kids were injured by the massive car bomb, along with university students who had been travelling in a bus, Capt Hussein said.

Gruesome photos of the scene show the twisted metal of burnt-out vehicles - some covered in blood - in the street.

The dead include many students and two Turkish citizens

An adviser to the capital, Hodan Ali, told Al Jazeera: “There are many casualties as well, so the death toll is expected to rise.”

Sakariye Abdukadir - who witnessed the explosion - said it had “destroyed several of my car windows. All I could see was scattered dead bodies... amid the blast, and some of them burned beyond recognition.”

Sabdow Ali, 55, who lives nearby, told Reuters that he had left his house after hearing the explosion, and counted at least 13 people dead. “Dozens of injured people were screaming for help, but the police immediately opened fire and I rushed back to my house,” he added.

The injured were transported to Medina Hospital, where a Reuters witness saw dozens arriving by ambulance from the scene.

President Mohamed Abdullahi Mohamed condemned the attack as “heinous” but did not mention the likely culprit, the al-Shabab extremist group, by name.

Bodies lay on the ground amid the blackened skeletons of vehicles. At a hospital, families and friends picked through dozens of the dead, gingerly lifting sheets to peer at faces. Hundreds of Mogadishu residents began to donate blood in response to desperate appeals.

Most of those killed were university and other students returning to class, Mayor Omar Mohamud Mohamed said at the scene. Two Turkish brothers were among the dead, Somalia’s foreign minister said.

“Some of those dead were police officers, but most of them were students,” witness Mohamed Abdi Hakim said. Somalis mourned the deaths of so many young people in a country trying to rebuild itself after decades of conflict.

There was no immediate claim of responsibility for the blast. But Al Qaeda-linked militant group al Shabaab, which wants to topple the United Nations-backed government, regularly carries out such attacks.

Although the extremist group was pushed out of Mogadishu several years ago, it continues to target high-profile areas such as checkpoints and hotels in the seaside city.

The worst of the attacks took place in October 2017, when a truck bomb left 512 dead and 295 wounded. On December 11 this year, five people were killed when Al-Shabaab extremists attacked a hotel popular with politicians and diplomats in Mogadishu. The police killed the two attackers.

In July, the former Mogadishu mayor, Abdirahman Omar Osman, was severely injured when a suicide bomber attacked his office, killing several people. The blast took place soon after United Nations envoy to Somalia James Swan had made a visit to the mayor’s office.

The same month, at least 26 people, including foreigners, were killed and more than 50 were wounded in an attack on a hotel in Kismayo in southern Somalia. Kenyans, Americans, a Briton, a Canadian and Tanzanians were among those dead along with a presidential candidate for regional elections. Jubbaland President Ahmed Mohamed blamed Al-Shabaab for the attack.