RIGA, LATVIA - A cruise ship with 984 people on board ran aground early on Sunday in the Baltic Sea, off the north-west coast of Latvia, the coast guard said.

The Bahamas-registered Mona Lisa had embarked from Kiel, Germany and was destined for the Latvian capital of Riga when it ran aground on a sand bank about 17km from the Latvian coast in the Irbe Strait between Latvia and the Estonian island of Saaremaa.

Latvian Coast Guard Service spokeswoman Liene Ulbina said the passengers, most of whom are German, were safe and not at immediate risk.

Coast Guard officer Ruslans Kulesovs said rescuers had begun an attempt to free the cruise ship, pumping out ballast water to reduce its weight.

Three tugboats would then attempt to pull the liner from an undersea sand bank, the Coast Guard officer said.

He had said passengers would not be evacuated before the rescue effort.

They had full use of the liner's onboard facilities, including access to fresh water, he added. Once the liner is freed, a team of divers would examine the ship's hull for signs of external damage, Mr Kulesovs said.

So far there has been no evidence that the Mona Lisa was damaged, Coast Guard officials said. Ms Ulbina said four Latvian ships were at the scene.