A U.S.-based rights group says Syrian commanders ordered security forces to shoot anti-government protesters to disperse them.

Human Rights Watch said Saturday that incidents involving the use of live ammunition on demonstrators were described by eight soldiers and four members of security force agencies who have defected since protests erupted in March.

The rights group says the defectors recounted situations in which they were initially told by superiors that they would be fighting militants. They instead encountered unarmed protesters, but commanders still ordered them to open fire.

Human Rights Watch says in its interviews with defectors, some said that they were told by superiors that they risked being shot if they refused orders to shoot demonstrators.

On Friday, activists said at least 13 people were killed during nationwide protests against President Bashar al-Assad. They say at least six deaths took place in the Damascus suburb of Dumair after security forces opened fire on demonstrators.

The Syrian government blamed “armed gangs” for some of the deaths.

Also, the state-run SANA news agency said pro-government rallies took place in several cities on Friday. The news agency said Saturday that Syrian youths were organizing another pro-government rally that would take place Sunday in the western city of Lattakia.