As Zimbabweans gear up to vote for a new leader on July 30, there are concerns that the upcoming elections could be marred by widespread violence.Speaking to reporters in Johannesburg on Thursday, Civil Society leaders from Zimbabwe said the elections in their country were going to take place in an "environment where the security of citizens is still a major issue".The briefing comes after Zimbabwean President Emmerson Mnangagwa survived a blast at a ruling Zanu-PF party rally at the weekend.Zimbabwean state media reported on Saturday that an explosion rocked the White City Stadium in Bulawayo where Mnangagwa was addressing thousands of his supporters.AFP reported earlier that Mnangagwa, who has claimed he was the target of the attack, said the blast was "calculated to achieve a bloodbath" and "destabilise the ongoing electoral programme"."There is a huge risk that we may not have a credible free and fair election in Zimbabwe on July 30," Human Rights Watch's Dewa Mavhinga told reporters.He said although Mnangagwa has made several assurances and pledged to deliver a fair and credible election, there were still major concerns ahead of the elections."He [Mnanganwa] is talking the right things [but] it is not clear whether he is walking the talk. The challenge which we have put to his administration is to deliver in terms of concrete steps to deliver credible and fair elections," he said.Mavhinga also said the attack at the weekend rally was concerning because "civilians do not have grenades under their pillows in their home, grenades are associated with the military and this is a challenge that perhaps this election could be very tense, and it might result in widespread violence."Meanwhile the chairperson for crisis in Zimbabwe coalition Rashid Mahiya said they wanted military to "reassert their commitment in upholding and protecting the constitution with respect to the elections and electoral processes".He also said the military should not interfere in the electoral process and that the Zimbabwe Electoral Commission (ZEC) should be professional in the way they operate.Mahiya said ZEC to publicly announce the names of the secretariat, their previous employers, experience qualifications and also the publication of public office bearers."We also ask ZEC to avail the complete and verifiable voters roll to all stakeholders particularly contesting political players. The voters roll has been the battle field for vote rigging in Zimbabwe and we want to make sure that the voters roll is clear and everyone has confident in it." * Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.