Sri Lankan President Maithripala Sirisena's youngest brother has died two days after he was attacked with an axe in what authorities say was a personal dispute.

According to a government statement, 42-year-old Priyantha Sirisena died in a private hospital in Colombo on Saturday. He was airlifted there from his hometown of Polonnaruwa in North-Central province following the attack on Thursday.

The attacker has surrendered to police. The statement did not say what the dispute was about.

Sirisena was in China on a four-day official visit when the attack took place.