Pakistan bus Srinagar, April 6, SPA -- Two suspected rebels opened fire and forced their way into a government guest house where more than two dozen passengers hoping to travel on the first Indian-Pakistan bus across Kashmir were being held, police and witnesses said. One of the attackers was killed and four people were injured, said Inspector-General of Police Javed Makhdumi and other security officials. Most of the sprawling quadrangular building was on fire and smoke poured out of windows as people jumped from the ground floor assisted by soldiers. The suicide raid was the biggest attack yet targeted at the bus service, set to be inaugurated Thursday by Indian Prime Minister Manmohan Singh. It will connect Srinagar and Muzaffarabad. No one claimed responsibility for the attack. However four Islamic militant groups, fighting Indian security forces in Kashmir since 1989, have threatened to disrupt the bus service. The fate of the passengers was not immediately known.