The FLA accuse Malian forces and Wagner mercenaries of intercepting two passenger vehicles.
The M23 draws its name from a peace agreement made on March 23, 2009.
Jerry Muhindo Kavali, 49, was injured two days ago by a bullet that struck the MSF office.
Digging into the status of Tutsis in DR Congo is an extremely complex and sensitive matter.
On Friday, the UK said there would be "consequences" for Rwanda over its alleged role in DR Congo.
Rwanda said Democratic Forces for the Liberation of Rwanda (FDLR) remains major destabilising force.
The invite comes at the end of a week which saw Kyiv excluded from US-Russia talks.
Treason is a capital offence in Uganda and if found guilty the 68-year-old could be sentenced to death.
The MFA added that the sides "paid special attention to promising projects in the sphere of peaceful space exploration."
