Mali has been gripped by uncertainty after the Group for the Support of Islam and Muslims (JNIM) teamed up with Tuareg rebels of the Azawad Liberation Front (FLA) in April to target ruling junta positions.

Since April 30, jihadists have blocked key routes into the capital, Bamako, which like the rest of the landlocked country, depends heavily on road imports.

"The ongoing siege of Bamako is having unacceptable consequences for civilians' freedom of movement and may lead to serious violations of their rights to food security, health and life," Amnesty said in a statement.

It urged JNIM to "respect international humanitarian law and ensure the safety of civilians", citing a May 6 attack on a convoy carrying civilian goods between Bamako and Bougouni in the south.

The trucks "were not under military escort and were not carrying military personnel or equipment", the statement read.

"Attacks on civilian vehicles with a civilian purpose are unlawful," Amnesty regional director Marceau Sivieude said in the statement.

"Under international humanitarian law, all parties to an armed conflict must always make a distinction between civilians and combatants."

More than a dozen transport companies earlier this week announced they were suspending routes to and from Bamako due to the blockade.

Since 2012, Mali has faced a deepening security crisis driven by violence affiliated with al-Qaeda and the Islamic State group, as well as separatists and community-based criminal networks.