Indian Prime Minister Narendra Modi has landed in Pakistan on a surprise visit in which he will meet his Pakistani counterpart Nawaz Sharif.

Modi was on his way back to India from Afghanistan when he stopped off in the eastern city of Lahore. The visit coincides with Sharif's birthday.

Modi is the first Indian PM to visit Pakistan since 2004.

"Looking forward to meeting PM Nawaz Sharif in Lahore today afternoon, where I will drop by on my way back to Delhi", Modi said on Twitter shortly before he landed in Pakistan.

Tensions between the two nuclear-armed neighbours have been high in recent years but relations have begun to warm.

(With inputs from BBC)