Tanzania has postponed a referendum on a new constitution after delays in registering voters, the electoral body said Thursday.
The postponement heightened tensions over the charter, which the main opposition parties have rejected. The delay also could complicate presidential and parliamentary elections due to be held in October.
The new constitution would replace one passed in 1977, when the state was under one-party rule. The opposition said it was approved last year without a quorum by an assembly dominated by President Jakaya Kikwete's Chama Cha Mapinduzi (CCM) party, which has been in power since Tanzania's independence from Britain in 1961.
The electoral commission said it had not received enough biometric voter registration kits to enable the vote on the constitution to take place as planned on April 30.
"The previously announced referendum ... has been postponed until the National Electoral Commission announces a new date," it said in a statement. "Since the registration of voters has not been completed, the electoral commission will not be able to proceed with the referendum on the new constitution."
Before quitting the constitutional assembly last April, opposition parties and civil society groups had sought limits on presidential powers and a federal system of government.
A group of bishops has urged Christian worshippers to vote against the proposed constitution, saying it was not written by an inclusive assembly. Kikwete, a moderate Muslim, warned clerics not to meddle in politics and said tensions between Muslims and Christians threatened peace.
Attacks on Christian and Muslim leaders over the past few years have raised concerns of an escalation of sectarian violence in relatively stable and secular Tanzania, east Africa's second-largest economy.
Tanzania's population of 45 million is roughly evenly split between Muslims and Christians.