Blasts ripped through three hotels in the Jordanian capital Amman around Wednesday midnight, killing at least 23 people, injuring more than 120.
According to television reports, the first blast hit the Radisson and was followed by a second blast at the Hyatt.
Agencies said the explosions occurred within minutes of each other.
"The attacks have been carried out in trademark al Queda way," a police source, who did not want to be named, said.
The explosions shattered the Radisson SAS, Grand Hyatt and Days Inn hotels.
The hotels, in the commercial area of Jebel Amman district, find regular bookings by US and European businessmen and diplomats, a report in the BBC
The Radisson is popular with Israeli tourists, and had often in the past been a target of several foiled al Queda plots.
The stone entrance of the Grand Hyatt had been completely destroyed, agencies said, adding that a wedding party with at least 200 guests was underway when the explosion went off at the Radisson.
Jordan is a key ally of the United States in its war against terror and had been hitherto escaped the terror attacks that rocked other parts of the Middle East.