AMMAN, Jordan - Police on Tuesday shot and killed three suspected terrorists who were believed to have planned to detonate a bomb that would have flattened a large part of Jordan's capital, security officials said.

Working on a tip, police stormed a hideout in east Amman where the suspects had been hiding, the police said in a statement carried by the official Petra news agency. A security official told The Associated Press that the three killed were believed to have links to a terrorist group that had plotted to attack the prime minister's office and Jordan's secret service with a powerful chemical bomb. The official spoke to the AP on customary condition of anonymity. The plot was disclosed earlier this week and was said to have been foiled last month. Had the bomb exploded, it could have killed at least 20,000 people and wrecked buildings within a half-mile, government officials have told the AP. The group is also believed to have planned to attack the U.S. Embassy and other diplomatic missions with poison gas, government officials have said. Police uncovered the plot late last month and arrested most of its members in two raids. In Tuesday's shootout, police called for the suspects to surrender, but they responded with gunfire, the statement said. The incident took place at 2:20 p.m. in the predominantly Palestinian district of Hashemi, the statement said. "Information made available to security authorities pointed to the presence of an armed group which had plotted to carry out terror attacks," the statement added. Two of the three men killed were foreigners, according to police. It was not immediately clear how many suspects were involved in the shootout and if any escaped. The government said that in the earlier sweeps that uncovered the bombing and chemical plots, police arrested an unspecified number of suspects and seized at least three cars filled with explosives and detonators. It said the suspects and their cars had entered Jordan from Syria, which denied the allegation. Twenty-two Arab men were convicted in a terror plot that targeted U.S. and Israeli tourists in the 2000 millennium celebrations in Jordan. Jordan, a moderate Arab nation with close ties to the United States and a peace treaty with Israel, has been targeted by the al-Qaida terror organization of Osama bin Laden (news - web sites) and other groups.