A pensioner was knocked over as men reportedly fought with knives in a busy McDonald’s in south-east London.
Police and paramedics rushed to the scene of the incident in Penge High Street at about 5pm on Monday.
The men who were involved in the brawl are thought to have fled before emergency services arrived.
A man who had attempted to break up the scuffle was injured, police said, but declined medical assistance.
A woman, aged in her 70s, was knocked over and seen by paramedics.
Her injuries are not thought to be serious.
A spokesman for the Met Police said: "Officers attended but any suspects or victims had left the scene, and no victim or victims were found having attended nearby hospitals.
"Enquiries by Bromley CID continue. No arrests have been made."