An elaborate attack by an Al Qaeda affiliate in Mali's capital this week killed some 70 people, diplomatic and security sources said on Thursday, while the government offered no figures on casualties.

Since the conflict in Mali erupted, violence has spread to neighbours in the Sahel region and reached the north of coastal countries. Thousands have been killed and millions displaced in the region, and some fighters are allied with Al Qaeda or Islamic State.

Insurgents hit base in Mali that hosts most of the country’s military aircraft and Russian mercenaries hired by military government for security.

An al-Qaeda-linked group has said it was behind an early morning attack in the Malian capital, Bamako. Armed men targeted a military training school and other areas in the city, the authorities said, blaming “a group of terrorists” for the assault.

More than 70 people are thought to have been killed in an attack by an al-Qaeda-linked group on Mali’s capital Bamako earlier this week, according to diplomatic and security sources.

Reuters reports, citing security and diplomatic sources in Africa, that approximately 70 people were killed in an attack by Jama'at Nasr al-Islam wal Muslimin, an al-Qaeda affiliate in Mali. The group launched an attack on a Police training center and the airport in Bamako, the capital of Mali, on Tuesday.

The West African country’s armed forces said the assault, on a school for military police, was carried out by terrorists.

This week, an Al Qaeda affiliate conducted a lethal attack in Mali's capital, killing around 70 people. The insurgents targeted a police training academy and the airport, undermining the junta's claims of improved security.