The Khojak Tunnel (Urdu: خوجک سرنگ, Khojak Sarang), is a 3.91 km (2.43 mi) railway tunnel in the Toba Achakzai range in the Qilla Abdullah District of Balochistan province, Pakistan.

[1] The tunnel was constructed in 1891 under the Khojak Pass, and was featured on the old Five Rupee banknote.

It was constructed in 3 years and it is so straight that a mirror can be used to reflect light at one end which is visible from the other.

The major railway line track laying and labor contractor was Waja Durra Khan Gorgigh Baloch from Karachi who originally migrated from Baho Kalat in early1800s and in his teen age year got his first contract when British were working on Karachi Port.

Later on he was awarded various railway contracts from Balochistan to Assam, Banglor and later Rangoon Burma, after his death his son took charge and British awarded his son Waja Fakir Muhammad Durra Khan the status of honorary judge in Karachi city court and after his death a road named after him from Badshahi road to 8 chowk Lyari.