Two little-know ethnic outfits from Nepal's restive Terai region have claimed responsibility for the serial blasts that left two persons dead and over two dozen injured in Kathmandu, just days after the government reached a peace deal with one of the major groups fighting in the south.

Nepal People's Army and Terai Army claimed that they had carried out yesterday's near-simultaneous blasts, local media said. The Terai Army had earlier claimed to have carried out blasts that injured over a dozen people in Rautahat district in May.

The weekend attack was condemned by the United Nations and major political parties, including the Maoists who termed it as an attempt to disrupt the Constituent Assembly polls to be held in November and derail the peace process.

Three suspects have been arrested in connection with the blasts, police said.

The Terai region has been witnessing a violent agitation since January by Madhesis who are demanding a greater share in the politics and the economy of the country.

Nepal's government reached a peace agreement on Thursday with one of the major ethnic outfits the Madhesi People's Rights Forum but about half a dozen armed groups were still operating in the region.

Security has been beefed up it the national capital and at vital installations across the country.

The government has mobilized security forces inside the Kathmandu valley and at sensitive areas around the country in view of the bomb attacks, a Home Ministry statement said.