Muslim leaders in eastern Nepal called for calm and authorities stepped up security Sunday after a bomb attack on a mosque killed two people and seriously wounded two others, officials said. The bombing Saturday was the first targeting a mosque in predominantly Hindu Nepal, where Muslims are a minority. No serious conflicts have occurred in the past between followers of the two religions. "We are trying to ensure that this will not lead to bigger conflict or communal violence," said Jafar Ahmad Jamali of the Muslim Ethihad Organization. A curfew imposed after the attack was lifted Sunday morning, but security had been stepped up in the region, said Madhav Raj Regmi, the chief government administrator. Police patrols have been increased, he said, and officers were being posted at all major intersections in the city. Jamali said plans were under way for a public funeral to be held later Sunday. "We have urged everyone to be on alert so there is no outbreak of communal violence," he said. The attackers tossed several bombs at the mosque in Biratnagar, a town 400 kilometers east of the capital, Katmandu, just after evening prayers. A group calling itself the Nepal Defense Army claimed responsibility for the attack. It sent a statement to the independent Kantipur Television network saying it "would continue such attacks until Nepal is reinstated as a Hindu nation." Nepal was declared a secular state in 2006.