Watch: Intruder jumps on table in Indian parliament
Chaos broke out in India's parliament on Wednesday after two men disrupted proceedings by shouting slogans and spraying coloured gas.
Reports say two others were detained for protesting outside parliament.
Their motive is not clear yet.
Visuals show a man in blue jumping across tables as MPs and security officials try to catch him.
The security breach occurred on the anniversary of a deadly terror attack on parliament in which 14 people - including the five attackers - were killed.
On Wednesday, lawmakers told reporters that they first thought someone had fallen from the visitors' gallery.
"Then we realised that it was a deliberate act of him jumping into the well. There was another person, both of them pulled out canisters which were emitting yellow smoke," said Congress MP Karti Chidambaram.