The second one — in which four Iraqis were briefly arrested last week — allegedly involved a plot to bomb a luxury hotel frequented by Americans and other Westerners, including about 70 journalists, the sources said on condition of anonymity.
Jordanian Information Minister Mohammad Affash Adwan indicated there had been Iraqi attempts to undermine Jordan's security but refused to elaborate.
"This is purely a security matter which is being investigated and I can't discuss it further," Adwan told The Associated Press.
The plot to contaminate water supplies involved five Iraqi diplomats expelled from Jordan on March 23, the sources said.
They said the water is pumped from Zarqa, 17 miles northeast of the Jordanian capital Amman, but refused to provide other details.
Zarqa water plants feed distant villages in Jordan's eastern desert, where there are several army and air bases, including one near the Iraqi border where hundreds of U.S. soldiers are manning anti-missile batteries.
The hotel involved in the second plot was identified by sources as the Grand Hyatt, where a small fire in one of the hotel's upper floors last week was blamed on an electrical short circuit. Hyatt officials only said they were unaware of a terror plot.
Iraqi Embassy spokesman Jawad al-Ali declined comment to the AP. But he told Paris-based Radio Monte Carlo that the allegations were "completely untrue" and that Iraq was keen to preserve Jordan's security.
Jordan said when it expelled the five Iraqi diplomats that they had carried out actions "incompatible" with their diplomatic duties. The government later said two could stay, but the Iraqi embassy said all five had already left the country.
Foreign Minister Marwan Muasher said the expulsions were ordered on "security" grounds. He and other government officials declined to elaborate, saying it was inappropriate to incite a public spat with Iraq as regional tension rose over the U.S. and British bombardment of Jordan's eastern neighbor.
One day after the deportations, Jordanian authorities detained four Iraqi transport officials for questioning. No details emerged from the interrogation, but officials said the four — two employees with Iraqi Airways and two with a joint Jordanian-Iraqi transport company — had been released.
Last week the State Department said it had information that Iraqi intelligence officers planned terrorist attacks against U.S. interests in two foreign countries, but declined to identify the two countries.
But CBS State Department Reporter Charles Wolfson reported, other administration officials said the countries were in the Middle East.
In both cases, the operatives were arrested, terrorist material was confiscated and attacks were not carried out, spokesman Richard Boucher said.
It is not clear if those arrests are connected to the latest foiled plots in Jordan.
Early last month, the State Department announced the three Iraqi diplomats remaining in Washington had been ordered to leave. The government called on about 60 countries with diplomatic ties to Iraq to expel 300 Iraqis said to be undercover agents possibly poised to attack American interests overseas.
Some of the 300 were operating as diplomats out of Iraqi embassies, U.S. officials said. Several countries expelled Iraqi diplomats then, citing spying accusations or their involvement in activities "incompatible with their diplomatic status."
After launching the war, the United States asked all countries to expel Iraqi diplomats and close their embassies. Few countries responded positively.
Jordan denied its expulsions were related to the U.S. request. But the actions fueled tension with Iraq, which already had been suspicious of Jordan for allowing U.S. troops to be stationed near its border, despite Jordanian assertions that the "several hundred" Americans were in the kingdom only for defensive purposes.
Aware of strong anti-war sentiments among Jordanians, the government has been striving to distance itself from the conflict on Iraq — supplier of all its oil needs at cheap prices. Trade with Iraq amounted to $700 million last year, making it the largest importer of Jordanian goods.
Jordan announced last week that oil from Iraq ceased on the first day of the war on March 20. Iraq blamed Jordan for the halted oil flow and accused the kingdom of blocking overland shipments of food and medicine. Jordan denied it, saying local exporters were concerned over road safety.