Two Americans were among at least five people killed in a grenade attack on a Protestant church packed with foreigners for a Sunday service in Pakistan's capital, a U.S. diplomat said. There was no immediate claim of responsibility, but suspicion fell on hard-line Islamic groups opposed to President Pervez Musharraf's support for the U.S.-led war on terror. Seven groups have been banned and hundreds of activists detained. "There are two Americans dead," a U.S. diplomat told Reuters, adding he could not release their names. A Pakistani and an Afghan were also among those killed, according to a police officer at a hospital where four of the dead were taken.