Nigeria, Jan. 28 -- According to the Associated Press, a man armed with a syringe sprayed an unknown substance at the Democratic congresswoman.

Security officers and police quickly responded as the incident unfolded amid rising tensions in the city over federal immigration enforcement.

The suspect was immediately tackled by attendees and security personnel, drawing loud cheers from the crowd.

Video footage obtained by NBC News and seen by The News Chronicle early Wednesday showed the man wearing a black jacket and holding a syringe as he was pinned to the ground with his hands tied behind his back.

The video revealed that the suspect had been sitting in the front row listening to Omar before suddenly standing up and spraying the subs...