CARACAS, Venezuela (AP) — An independent presidential candidate running against Venezuelan leader Nicolas Maduro says government supporters have physically attacked his campaign.

Henri Falcon said Monday on Twitter that a congressmen campaigning with him in a poor neighborhood was struck by a man wearing steel knuckles, sending him to the hospital with a serious head injury.

Falcon is a prominent candidate against Maduro in the May 20 election.

Falcon wasn't hurt, and he's calling on Maduro to bring his supporters under control.

Falcon says several people campaigning with him through one of the largest slums in the country had been stripped of their belongings and then assaulted.

Falcon recently launched his campaign, breaking with the opposition alliance that refused to participate in an election it says has been rigged by Maduro.