The regime of Ali Abdullah Saleh has off and on switched between its use of rubber bullets against protesters and live ammunition, and now, doctors say, it is swapping out traditional tear gas for a banned nerve agent of some sort.

Doctors at the scene of one of the “tear gas” attacks say that the victims showed symptoms of the gas targeting their central nervous system and as a paralytic, banned under international law. Traditional tear gas is supposed to only produce symptoms in the respiratory system.

One of the doctors, Mohammad al-Sheikh, said that some of the victims have to wear diapers now because they have lost all muscle control. He added that he had never seen “tear gas” causing these sorts of symptoms before.