DHAKA: Ukraine has begun commemorations to mark the 30th anniversary of the nuclear disaster in Chernobyl.

Sirens were sounded at the same moment as the first explosion at the reactor, in the early hours of 26 April 1986, reports the BBC.

The meltdown at the plant remains the worst nuclear disaster in history.

An uncontrolled reaction blew the roof off, spewing out a cloud of radioactive material which drifted across Ukraine's borders, into Russia, Belarus and across a swathe of northern Europe.

A memorial service is being held at the town of Slavutych, built to re-house workers who lived near the nuclear plant.

Later on Tuesday, Ukraine's President Petro Poroshenko will attend a ceremony near the site and a church service will be held in Kiev for the families of victims.

BDST: 1021 HRS, APR 26, 2016
SR