Police said a group of armed robbers entered Rishilpi (a non-government organisation) complex and tied up the night guards. They broke into the NGO building and looted cash and valuables and hacked indiscriminately Dutch national Yan Branshautt and his wife Nelly.

Hearing the couple's scream, locals rushed there and took them to a hospital.

The police nabbed four people including three night guards for their alleged involvement in the robbery.

The officer-in-charge of Kotwali Police Station said they are interrogating the guards -- Nurul Islam, Ashok Kumar and Pradip -- and arrested a youth -- Alaudding of Magura village in the sadar upazila.