COLOMBO, Sri Lanka -- Snipers assassinated Sri Lanka's foreign minister at his home yesterday, and the military blamed the separatist rebels whom the slain official had worked to ostracize internationally as a terrorist group.
President Chandrika Kumaratunga declared a state of emergency today amid fears that the killing of Lakshman Kadirgamar, 73, would threaten a cease-fire between the government and the Tamil Tiger rebel group -- a truce already shaken by a two-year stall in peace talks.
Kadirgamar, himself a member of the ethnic Tamil minority, was shot in the head and heart about 11 p.m. yesterday local time after finishing a swim and was taken to the National Hospital, where he died.
''The minister had just returned from a swim and was getting inside his home when he was shot," Inspector General of Police Chandra Fernando said. He said there were two snipers hiding in buildings near Kadirgamar's heavily guarded home in the capital's diplomatic district.
Authorities began house-to-house searches in the area and made two arrests at a neighboring house.
Kumaratunga declared a nationwide state of emergency to ''facilitate enhanced security measures and effective investigations of this act of wanton terror," her office said. ''The president appeals for calm and restraint in the face of this grave and cowardly attack upon Sri Lanka."
As dawn broke, dozens of military trucks moved in and soldiers were seen positioning at all important road intersections in the capital.
The emergency law, used at the height of the conflict between the government and the Tamil Tigers, allows authorities to detain without trial anybody suspected of involvement in terrorist activities.
Kadirgamar was a close aide to Kumaratunga. The Oxford-educated lawyer led an international campaign against the Tigers, who remain on terrorist lists in five countries, including the United States and Britain.
Brigadier Daya Ratnayake said that over the past week police had arrested two Tamil men who were taking video of the area.
''We have reasons to believe that he was killed by the Liberation Tigers of Tamileelam," Ratnayake said, using the rebels' formal name. ''He was always under threat and had one of the best protections."
The justice minister, John Seneviratne, was more cautious.
''We can't say as yet who's behind this, but the minister had been getting threats," Seneviratne said outside the hospital.
Rebel attacks against Sri Lankan political leaders were once common.
Kumaratunga, who rushed to the hospital after the shooting, was herself gravely wounded in an assassination attempt in 1999. Police blamed Tamil rebels for that attack, which killed 26 people.
Such high-level attacks stopped after a February 2002 cease-fire, but tensions have been growing lately between the government and the rebels. There has been a surge of attacks in the volatile eastern region, occasionally spilling into the capital, Colombo.
''The situation has deteriorated," Hagrup Haukland, chief of the cease-fire monitors said. ''It's a big, big blow to the cease-fire and the whole peace process irrespective of who is behind this."
He said it was ''too early to speculate if there was going to be an outbreak of war," but added that he had informed monitors in district offices to be on the alert.
Elite police forces and soldiers condoned the area around Kadirgamar's home, and the air force deployed helicopters to search for the assailants. Authorities tightened security at all entry and exit points to the city.
The Tamil Tigers began fighting in 1983 for a separate homeland for ethnic Tamils in the country's north and east, claiming discrimination by the majority Sinhalese. The conflict killed nearly 65,000 people before the Norway- brokered cease-fire.
Post-truce peace talks have been stalled since 2003 over rebel demands for wide autonomy in this country of 19 million people. Sri Lanka, an island nation about the size of West Virginia, is less than 20 miles from the southeast coast of India.
The United States denounced the assassination.
''This senseless murder was a vicious act of terror, which the United States strongly condemns," Secretary of State Condoleezza Rice said in a statement.
Rice urged Sri Lankans not to let the assassination lead to resumed civil war.