BAGHDAD: Clashes among rival Shiite Muslim militants in the southern Iraqi city of Basra took place overnight and into Thursday morning, killing four, local security officials said.

The skirmishes were the latest violence to hit the country in a political crisis that pits followers of the powerful Shiite cleric Moqtada Al-Sadr against mostly Iran-aligned parties and paramilitary groups.

The security officials said the clashes took place in the center of Basra, Iraq’s main oil-producing hub.

Violence re-erupted in Iraq this week as armed supporters of Sadr fought with security forces and Iran-aligned gunmen in Baghdad in the fiercest street battles the capital has seen for years.

An intractable political deadlock between the two rival Shiite camps has left Iraq without a government since an October election. It has also deepened dysfunction and instability as Iraqis struggle to move on from decades of war, sanctions, civil strife and endemic corruption.