The first breakthrough in the 21-km tunnel being constructed between Bandra-Kurla Complex (BKC) in Mumbai and Shilphata in Thane for the Mumbai-Ahmedabad bullet train project has been achieved, the National High Speed Rail Corporation Limited (NHSRCL) said on Thursday, reported news agency PTI.

The first breakthrough in the 21 km long tunnel was recorded on Wednesday, an NHSRCL release informed.

With this, a 2.7-kilometre continuous tunnel section between has been successfully completed using the New Austrian Tunnelling Method (NATM), the release added, reported PTI.