Harbour lines services were restored after completing restoration work at Andheri on war footing, informed Western Railway.
Meanwhile, the railways are working to reinstate all the remaining sections as well.
The first train for CSTM from Andheri left at 14.15 hrs.
Six people have been injured in the incident.
The Gokhale Bridge, which collapsed, connected Andheri East and Andheri West. It collapsed on the tracks near Andheri Station, affecting the transport services at worse.
Maharashtra Chief Minister Devendra Fadnavis, taking stock of the situation, spoke to the Commissioner of Police of Mumbai and asked him to ensure smooth traffic movement.
Meanwhile, Fadnavis also asked the Brihanmumbai Municipal Corporation (BMC) commissioner to increase the frequency of BEST buses for the convenience of commuters.
Union Railway Minister Piyush Goyal, on the other hand, directed officials to speed up repair work and rapidly restore traffic in close coordination with other departments.
“I’ve ordered an inquiry by Commissioner of Rail Safety”, the Railway Minister added.