Violence continues to mar the election campaign in Nigeria, with at least 15 dead in two southern states and violence between rival factions of the same party breaking out at a political rally in Lagos. Nigeria returned to civilian rule in 1999 after three decades of almost continuous military dictatorship, and the 2007 polls should mark the first time one elected government hands over to another through the ballot box. However, violence remains a feature of political life. The use of paid thugs to intimidate opponents or voters is a common tactic by politicians in many of Nigeria's 36 states, while political assassinations have also occurred. The People's Democratic Party (PDP) held a colourful rally in Lagos the country's commercial capital on Sunday (July 23) to campaign for its parliamentary candidates who arrived at the gathering and were immediately mobbed by die-hard supporters. The PDP is chaired by president Olusegun Obasanjo who led the party to parliament with a marjority win in the country's 2003 elections amidst widespread cries of rigging and foul play. President Obasanjo will not be contesting next years elections as his bid to run for a third term was thrown out of parliament early this year. Confident his party would still be victorious, Rasheed Williams, Lagos State Chairman of the PDP said: "You can see that as at today there is no other political party in existence, they have printed posters but they can not indicate the party they belong". Fighting later broke out at the PDP rally when rival factions within the party clashed leaving 15 people injured and other fleeing the scene as the police confronted the rioters.