Explosions hit three hotels in the Jordanian capital Wednesday night, and at least 18 people were killed and 120 wounded.
A police official said the explosions indicated the involvement of al-Qaida, which has launched coordinated attacks on high-profile, Western targets in the past.
The first blast occurred at about 8:50 p.m. at the luxury Grand Hyatt hotel, popular with tourists and diplomats, and completely shattered its stone entrance.
Associated Press reporter Jamal Halaby, who was at the hotel, counted seven bodies being taken away and many more wounded being carried out on stretchers.
A few minutes later, police reported an explosion at the Radisson SAS Hotel a short distance away. Police said five people were killed and at least 20 were wounded in the blast at a wedding hall. The hotel is popular with American and Israeli tourists and was the target of a plot in 2000.
A third explosion was reported at the Days Inn Hotel, and police said there were casualties.
Police had no word on what caused the explosions, although an American businessman at the Grand Hyatt said a bomb went off in the lobby. Witnesses saw smoke rising from the building.
Jordan, a close U.S. ally, has arrested scores of Islamic militants for plotting to carry out attacks in the moderate Arab kingdom. It has also sentenced numerous militants to death in absentia, including the Jordanian-born leader of al-Qaida in Iraq, Abu Musab al-Zarqawi.
In July, prosecutors indicted five Jordanians in an alleged conspiracy to attack intelligence agents, tourists and hotels in Amman. Al-Zarqawi has not been linked to the alleged plot.
U.S. officials believe al-Zarqawi and bin Laden operations chief Abu Zubaydah were chief organizers of a foiled plot to bomb the Radisson SAS Hotel.
The attack was to take place during millennium celebrations, but Jordanian authorities stopped it in late 1999. Abu Zubaydah was captured in March in Faisalabad, Pakistan, in a raid by the CIA, FBI and Pakistani authorities. Al-Zarqawi remains at large.