Jordan has foiled a planned suicide bomb attack on "a vital civilian installation," official state-run media has reported.
Two Iraqis and a Libyan, believed to be members of the al-Qaeda terror network, have been arrested in connection with the plot, state television said.
Police are said to be hunting several other militants, including a Saudi and three Iraqis.
In November 2005, 60 people died in a triple hotel bomb attack by al-Qaeda.
Jordanian government spokesman Nasser Judeh said the militants had planned to attack a "vital civilian facility" in the capital in Amman, but he refused to give further details about the nature of the target.
Mr Judeh told the Associated Press that police had made the arrests after gaining new intelligence.
State-run TV showed photographs of the three detained men, along with images showing automatic rifles and bomb making materials.
"The intelligence services seized 4kg (8.8lb) of heavy explosives," a statement from an unnamed security official read out on state TV said.
Four more suspects are still on the run and are believed to be in a neighbouring country, according to Jordanian officials.
The attempted attacks sound very similar to the November suicide bombs, the BBC's Jon Leyne in Amman says.
Al-Qaeda has been trying to use non-Jordanians to carry out attacks in Jordan because the intelligence services monitor local al-Qaeda sympathisers very closely, our correspondent says.
Jordan has clamped down on Islamic extremists in the wake of last November's deadly bomb attacks on three hotels in Amman, which were carried out by al-Qaeda in Iraq.
Sixty people died in the attacks, including three suicide bombers.
Correspondents say that before the attacks the group's leader Abu Musab al-Zarqawi appeared to enjoy a certain sympathy in some sections of Jordanian opinion, but that November's attacks eroded that sympathy very sharply.