Four persons died and 51 others were seriously injured after an old iron pedestrian bridge on the Indrayani river collapsed on Sunday afternoon in Pune`s Maval tehsil, prima facie due to crowding by tourists who ignored the warning board at the spot, officials said.

The bridge, which was around 30 years old, connected nearby villages and was a common route for locals and tourists. At the time of the incident, around 100 to 125 tourists had gathered at the location, an official statement said on Sunday.

Following the incident, a massive rescue operation was immediately launched. Teams from the local administration, National Disaster Response Force (NDRF) (2 units), Pimpri-Chinchwad Police, Central Reserve Police Force (CRPF), Disaster Mitra volunteers, PMRDA Fire Department, and members of Shivdurga and wildlife organisations joined hands in search and rescue efforts.