A policeman inside the McDonald’s outlet on Friday. Picture by Sanjoy Chattopadhyaya

Panic gripped Park Street on Friday afternoon after a fire alarm went off at McDonald’s, where a blast on Sunday morning killed a 24-year-old pedestrian.

A McDonald’s source said the alarm went off around 3.45pm after a security guard lit a cigarette in the toilet.

The siren-like sound, which owners of adjacent stalls said continued for five minutes, sent commuters scurrying for cover on the rain-drenched street.

Police rushed in and cordoned off one flank of Park Street — on the McDonald’s side. After two fire tenders reached the spot, the entire street was blocked.

The firemen took around 15 minutes to inspect the outlet, shut since the August 12 explosion, and give the all-clear sign.

One flank of the road was again opened to traffic, but by then there was massive congestion on and around Park Street. The barricade was lifted after half an hour.

“The Sunday blast was still fresh in our minds, so we did not want to take any chances,” said Gyanwant Singh, the deputy commissioner of police (headquarters).

“I did panic when I heard the alarm, fearing a repeat of Sunday’s tragedy that killed Aftab Hussain Ansari,” said B.N. Pandey, 70, who sells books on the Big Mac pavement. “That moment on Sunday morning flashed through my mind — I was arranging my books when I heard a deafening blast and felt a gust of hot air on my face.”

The panic on Park Street on Friday evening was short-lived but sharp. “Everyone ran for cover,” said Kuldip Yadav, a resident of Park Street. “Someone said there was a gas leak, another said there was a blaze. But the firemen assured us there was no cause for panic.”