Environmentalists are investigating the incident, the ministry said in a press release.
A forecast by the Environmental Protection Agency shows that the oil slick is moving toward Latvia's territorial waters and is unlikely to reach the coast in the next three days, it said.
Once the amount of pollutants released into the sea has been determined, the Environmental Protection Department under the Health Ministry will calculate the environmental damage that will have to be compensated for by the terminal's owner, according to the press release.
Environment Minister Simonas Gentvilas said the extent of the environmental damage would depend on meteorological factors.
"Wind and waves create favorable conditions for the pollutants to disperse and dissipate. On the other hand, low temperatures are hindering nature from coping on its own," he said in the press release.
The incident was reported to the authorities at around 10 a.m. on Monday.
The Lithuanian Navy's Maritime Rescue Coordination Center has sent a helicopter to the area to measure the size of the oil spill.
Orlen Lietuva confirmed on Monday afternoon that crude oil had spilled into the terminal's water area due to a mechanical damage.
"Orlen Lietuva's tugboats and its emergency response team are currently working at the scene of the accident and the company's security team is patrolling and watching the coast," the company told BNS in a comment.
"The Baltic Sea coast from Sventoji to Liepaja has been inspected and no pollution has been detected," it said.
Orlen Lietuva said the oil spill had been stopped, adding that the exact amount of pollutants released into the environment would be known later.
The company said it had set up a commission to investigate the incident which it said would not affect its operations.
Orlen Lietuva has been importing crude via Butinge since 2006 after Poland's Orlen purchased the crude refinery near Mazeikiai, in northwestern Lithuania.
Two oil spills occurred at the terminal in 2001, several years after its launch in 1998.
In November 2001, 59 tons of oil spilled into the sea when a sub-sea hose cracked. Ten tons of the oil were collected and the damage to the environment was estimated at 2.6 million litas (0.75 million euros). Prosecutors launched a criminal case over the pollution incident.
It was said then that the hose manufacturer recommended replacing them every three years, but this was not done.
In March 2001, a cable connecting the North Pacific to the buoy and, later, pumping hoses broke off due to high winds while pumping oil onto the Norwegian tanker. Three tons of oil spilled into the sea during the incident and some of it reached Latvian waters.
The first time Butinge's pumping hose tore open was in December 1999, but no oil was released into the sea in the incident.
Another incident occurred during the unloading of the Stena Antarctica tanker at the buoy in January 2008. It was said that around 400 kilograms of oil had been spilled into the sea and reached the coast off the Lithuanian seaside resort of Sventoji.
