At least three people, including a woman, were killed Monday in a powerful petrol bomb blast in the Nepali capital, media reports said.
More than six people were injured -- five of them critically, Xinhua reported.
Local media reports said the blast took place around 1 p.m. outside the gate of the Nepal Oil Corporation's central office in Babarmahal area, close to the country's seat of government Singhadurbar.
The Samyukta Jatiya Mukti Morcha-Bishwokranti (SJMM), an ethnic outfit, has claimed responsibility for the bombing.
Police cordoned off the site immediately after the incident. The injured were admitted to the Bir Hospital.
Local media said a meeting on fuel price hike was underway in the Nepal Oil Corporation's office when the explosion rocked the building.
At least six people were also injured in the blast, officials say.
There has been no comment from the government as yet.
"A bomb blast killed two people and injured five in an area near government offices and the district court. The explosion occurred at 1:25pm (0740 GMT)," Nepal police spokesman, Binod Singh, was quoted by news agency Agence France Presse as saying.
"A special team of police have been deployed in the area. They are gathering evidence and the area has been cordoned off."
A person claiming to be a spokesman for the Unified National Liberation Front said it was a group fighting for the rights of indigenous communities and cited the government's inability to curb corruption and fuel price rises as reasons behind the attack, BBC Nepali reports.
The device, which went off at 1:25pm (0740 GMT) in a busy area of Kathmanduas workers were heading out of offices on their lunch breaks
A previously unknown group calling itself the Unified Ethnic Liberation Front claimed responsibility, Home Minister Bijay Kumar Gachchadar said, although the group’s agenda remains unclear.
“We will take action against the group. This is a political group which the police are investigating,” he told AFP.
“This is a very serious incident. Two were killed on the spot and one died in hospital. Seven were wounded.
“This is not due to a lapse in security but it represents an ongoing threat. I have ordered that security be tightened.”
Live television pictures from outside the offices of the state-owned Nepal Oil Corporation (NOC) showed blood spattered across the road while police cleared panicked office workers from an area surrounding a body.
“We rushed to the site after hearing the explosion. There was panic and crying,” said Ramesh Koirala, chief of the NOC’s administration department.
“I saw that one body was piled up on another. The police haven’t picked up the dead bodies yet. There were internal organs scattered across the road. One of our employees, who is in his 30s, has been seriously injured.”
Another witness told News 24 TV: “There was a sudden explosion while we were talking and we ran for cover.
“We assumed that sound of the explosion was from a punctured tyre but we quickly realised that it was a bomb blast.”
Three people were killed and two others injured in December 2009 when a bomb went off in the southwest of the country but the device was thought to be a left-over from the Maoist insurgency.
