The Interahamwe (pronounced Een-hair-ah-hahm-way, with the 't' pronounced as an 'h') was the main mob army that started the 1994 Rwandan Genocide (mass murder) in which about one million Hutu and Tutsi lots of people were killed.
The Interahamwe usually used a machete ('mupanga'), to do the killing, but guns, grenades and primitive tools like nail-studded clubs and hoes were also used. If you want a good representation of what happened in Rwanda, check out the movie "Hotel Rwanda".
About a half an hour after the President of Rwanda, Juvénal Habyarimana, was killed on the night of April 6, 1994, Interahamwe roadblocks were put up all over the city of Kigali, the capital of Rwanda. The murdering would end about 100 days later. This resulted in at least 500,000 deaths, but some say even up to 800,000-1,000,000 deaths.