Were the murder of tupac and biggie smalls related?

What possible reasons do you think that these two rappers were targeted? Were they involved in some kind of a turf or gangland war? Were they both killed by the same killers? or were their killers working together? oh and by the way the reason I said killers is that i know that both murders were planned by not one but a group of people and that tupac was shot by one person but there was also another person driving the limo and probably more than just two people in the limo.