CARACAS, Venezuela (AFP) — More than 700 people arrested during protests that erupted after Venezuela’s disputed presidential election have been transferred to maximum security prisons, a human rights group said Saturday.

The detainees, who had been held at police stations around the country, were transferred over the past week to two notorious prisons that were previously controlled by gangs, the Venezuelan Prisons Observatory said.

In many cases the transfers were conducted under questionable circumstances, with some detainees’ relatives not informed of the moves to Tocuyito and Tocoron prisons, the group said.

“They were conducted with many irregularities,” the NGO said in a press release.

More than 2,400 people were arrested after the protests that broke out after President Nicolas Maduro was declared winner of the disputed July 28 election.

The opposition claims it won by a landslide and has voting records to prove this.

The leftist Maduro government, brushing off accusations of authoritarianism, has resisted intense international pressure to release vote tally numbers to back up its claim of victory.

The United States, the European Union and several Latin American countries have refused to recognise Maduro as having won without seeing detailed voting results.

Violence that accompanied the protests left 27 people dead and 192 injured.

The prison advocacy group said none of the people transferred to maximum security facilities have been allowed to contact their families or attorneys.

Of the 2,400 detainees, 1,581 have been listed as political prisoners by another advocacy group, called Penal Forum.