A general view of Tunisia’s Constituent Assemblyat the beginning of voting on the country’s draft constitution in Tunis January 3, 2014. REUTERS/Zoubeir Souissi

Death threats against Tunisian secular lawmakers on Sunday disrupted voting on a new constitution, underscoring tensions over the role of Islam and the transition to democracy three years after the nation’s revolution.

Tunisia’s parliament started voting last week on the new charter, which is meant to put democracy back on track after deadlock between ruling Islamists and secular parties since the 2011 fall of autocratic leader Zine al-Abidine Ben Ali.

Approving the constitution is a key step before a caretaker government takes office to end the crisis between Islamists and secular opponents and prepare for new elections later this year.

Members of the national assembly have approved several articles of the new constitution, but on Sunday, Mongi Rahoui of a leftist opposition party and two other secular opposition members received anonymous death threats, officials said.