Zimbabwe police have arrested four people for publishing "falsehoods and hate speech" on social media, a newspaper reported.The suspects weren't named, and the state-run Sunday Mail did not say what law the four are being charged under."I want to warn those that abuse social media that we have mechanisms to catch them if they commit crimes," senior police officer Erasmus Makodza told the paper. Last week Makodza said police would arrest people who used social media to spread misinformation on a controversial postal vote by police officers that began on Thursday.Right to informationThe opposition Movement for Democratic Change (MDC) Alliance alleged police officers were forced to vote in front of their commanding officers, a charge denied by the police. In a statement, the Media Institute of Southern Africa (MISA) said the right to share factual information on social media must be upheld, even if it is critical of the Zimbabwe Electoral Commission (ZEC). "MISA reminds the government that the sharing of information should not be criminalised during the electoral cycle," MISA added. Death threatsLast week a top official from ZEC says she received death threats on Twitter.Netsai Mushonga said she got a message via the micro-blogging site from someone threatening to shoot her, reports the state-run Sunday News. The ZEC has come in for intense criticism both on and offline for lacking transparency and allegedly showing bias towards the ruling Zanu-PF party ahead of polls on July 30.