MOSCOW -- Three hundred relatives of the seamen who died aboard the Russian submarine Kursk when it sank on a naval exercise in the Barents Sea a year ago held a memorial ceremony Sunday at the sub's home port of Vidyayevo, near Murmansk.

The relatives observed a minute's silence in a brief ceremony, attended by the head of Russia's Naval Forces Admiral Vladimir Kuroyedov, at the stone laid where a monument to the 118 seamen is to be built, the Interfax news agency reported.

The somber-faced relatives, who had arrived in the naval garrison on Russia's Kola peninsula Saturday, laid flowers at the spot under an overcast sky.

To a drumbeat and the playing of a military band, as the rain paused and the sun broke through, a guard of honour laid wreaths while the relatives laid red carnations.

The relatives were due later go to the base from which the Kursk sailed on its fateful voyage to attend a full memorial service.

Church services were being held across Russia in honor of the seamen who died on August 12 last year when the Kursk sank in circumstances which, even a year later, have yet to be explained.