European officials told The Associated Press that schools were among the potential targets.

The warnings came a day after U.S. Secretary of State Hillary Rodham Clinton testified to Congress about the Sept. 11 attack on the U.S. diplomatic mission in Benghazi that killed four Americans, including the U.S. ambassador to Libya. They also came as French troops battled al-Qaida-linked militants in the West African nation of Mali, and followed the deaths of at least 37 foreign hostages seized by Islamist extremists in Algeria.

It was unclear if those two events were linked to the latest concerns about Libya.

The foreign ministries of the three European countries issued statements describing the threat as specific and imminent but none would elaborate.

The U.S. Embassy in Tripoli, Libya’s capital far to the west of Benghazi, said there was “no specific information pointing to specific, imminent threats against U.S. citizens.”

With a population of 1 million, Benghazi is Libya’s second-largest city and where the Libyan uprising against longtime dictator Moammar Gadhafi began in February 2011. Gadhafi was eventually toppled and killed after NATO backed the rebel movement, and the Arab country has since struggled with increasing insecurity.

Al-Qaida-linked militants operate in Libya alongside other Islamist groups, and the country is awash in weapons looted from Gadhafi’s many military depots.

Schools, businesses and offices of non-governmental organizations were among the possible targets, according to two European officials familiar with the threats. They spoke to the AP on condition of anonymity because they were not authorized to be quoted by name in the media. They refused to give any other details.

Violence in Benghazi has targeted both foreigners as well as Libyan officials in recent months, with assassinations, bombings and other attacks.

It was not immediately clear how many people were affected by the European warnings. Britain’s Foreign Office said “dozens” of its citizens were in the city, while Dutch spokesman Thijs van Son said four Dutch citizens were registered there, and possibly two more were in the city. A German Foreign Ministry official, who requested anonymity because government policy did not allow him to be quoted by name, said “very few” Germans were in Benghazi. A Canadian Foreign Affairs official said an email was sent to Canadians there advising them to leave.

Several countries have for months advised against all travel to the city, especially after the U.S. mission was attacked. Residents say many foreigners had already left in recent weeks.

Air Malta canceled Thursday’s flights between the Mediterranean island and Benghazi following the British advice, but said flights to Tripoli were not affected. The airline said its next flight to Benghazi was scheduled for Tuesday, adding that it will keep reviewing the situation.

Adel Mansouri, principal of the International School of Benghazi, said U.K. and foreign citizens were warned in the last few days about a possible threat to Westerners. He said the school’s teachers were given the option of leaving but decided to stay.

The school has some 540 students. Most are Libyan, with some 40 percent holding dual nationality. Less than 5 percent are British, while 10 to 15 students have U.S.-Libyan nationality, he said. Classes were not due to resume until Sunday because of a holiday Thursday.

“We told the British ambassador we are staying, and we’ll be in touch,” said Mansouri, who has both Libyan and British citizenship. “We don’t see a threat on the ground.”

Saleh Gawdat, a Benghazi lawmaker, said French doctors working in the city’s hospitals have left and the French cultural center was closed over concerns about potential retaliation for the French-led military intervention against Islamist militants in Mali, which began two weeks ago.

In addition to the deadly Sept. 11 attack on the U.S. mission, an Italian diplomat’s car was fired on by militants in Benghazi earlier this month. The consul, Guido De Sanctis, wasn’t injured but the attack prompted Italy to suspend its consular activities and send its foreign staff home.

Islamist extremists in the area are often blamed for targeting security officials who once worked under Gadhafi, taking revenge for those who tortured or imprisoned them in the past. Many residents also accuse Gadhafi loyalists of trying to undermine Libya’s new leaders by sowing violence.

Fawzi Wanis, head of the Supreme Security Committee in Benghazi, said he did not know of an imminent threat, but “in general it is possible that something happens” in connection to Mali.

Ibrahim Sahd, a Benghazi-based lawmaker and politician, said the new government is putting together a plan to beef up security in the city and this “might have caused the Westerners to worry about a backlash.”

Noman Benotman, a former Libyan jihadist with links to al-Qaida who is now an analyst at London’s Quilliam Foundation, said other groups inspired by the terror network have been gaining a following in Libya since Gadhafi’s fall. There have been nearly a dozen attacks against Western targets in Libya recently, he said.

“It’s the same al-Qaida ideology that is driving these militants,” Benotman said.

Oil companies working in other parts of Libya said they were aware of the European warnings to foreign citizens in Benghazi but said there were no immediate plans for evacuations.