A man jumped into the lawmakers’ area of India’s parliament, shouted slogans and set off a smoke can on Wednesday, in a major security breach on the 22nd anniversary of a deadly attack on the complex.

The parliament TV channel showed a young man wearing a black jacket and dark trousers jump from the visitors’ gallery into the lawmakers’ seating area in the lower house while a member was speaking, climbing over tables and entering the aisles.

He was surrounded by security staff and lawmakers and caught in an aisle as he set off a smoke can in his shoes, releasing dense white and yellow smoke, lawmakers said.

Four people, including the man, were arrested, authorities said.

“It all happened in half a minute or one minute,” Rajendra Agarwal, a lawmaker from the ruling Bharatiya Janata Party who was presiding over the house, told CNN News 18 TV channel, adding he saw a second person in the visitors’ gallery also trying to jump into the lawmakers’ area.

“There is no doubt it was a major security lapse,” he said.

Lawmakers said the intruder shouted slogans they could not make out and there was a sound and some smoke.

Prime Minister Narendra Modi was not in parliament at the time.

Lawmakers shaken

“I was expecting maybe they will blast something, shoot somewhere,” Sudip Bandyopadhyay, a Trinamool Congress party lawmaker, told the ANI news agency in which Reuters has a minority stake.

“This is a serious security lapse. How did they enter […] releasing smoke, sound,” he said.

The lower house stopped proceedings soon after the incident but resumed business about an hour later.

Speaker Om Birla told members that investigations found that the smoke released by the man was “ordinary smoke, just to cause sensation”.

Two people were arrested from inside the building and two from outside the complex, he said.

There was no statement from the government or law enforcement agencies.

The incident took place in the new, high-security parliament building inaugurated by Modi in May.

In 2001, more than a dozen people, including five gunmen, were killed in an attack on the old building in the same complex, which New Delhi blamed on militants.

Following the attack, India and Pakistan mobilised one million troops on either side of their border and were on the verge of war before months of global diplomacy averted it.

The parliament complex is located in the heart of New Delhi’s power centre and security is high in and around it, especially when it is in session.

The complex has its own security personnel for protection inside the building, paramilitary personnel providing a second ring outside and Delhi Police forming a third, outer ring.

Visitors can secure a pass to enter parliament and watch proceedings on the recommendation of lawmakers.

These passes were being stopped temporarily and a complete security review is being conducted, a parliament official said.