LONDON — Britain, Germany, the Netherlands, and the United States issued ominous warnings Thursday about threats to Westerners in Libya, in particular the unruly eastern city of Benghazi, less than a week after the deadly hostage crisis in neighboring Algeria.
Travel advisories issued by the foreign ministries of the three European countries did not elaborate on the precise nature of the threat, nor was it clear how many expatriates might be affected, but they warned their citizens to leave Benghazi immediately.
Hours later, the United States, which has admonished Americans to avoid Benghazi since the deadly attack on a US diplomatic compound there on Sept. 11, took note of the European advisories in an ‘‘emergency message’’ for US citizens who might be in Libya or preparing to travel there.
“Although there is no specific information pointing to specific, imminent threats against US citizens, the potential for violence and kidnappings targeting Westerners in Benghazi is significant,’’ read the American message, posted on the website of the US Embassy in Tripoli, the capital. ‘‘We strongly encourage all US citizens to take appropriate precautions, as the security situation in Libya is volatile.’’
The message urged US expatriates to heed a Jan. 2 advisory issued by the State Department that broadened a warning to avoid travel to Benghazi to include many other parts of Libya because of the lawlessness and instability that have troubled the country since the overthrow of Moammar Khadafy more than a year ago.
Benghazi, Libya’s second-biggest city and the base of the revolution that overthrew Khadafy’s autocracy, has come to symbolize the problems in Libya and the impunity of regional militias, including some with Islamic militant ties that are believed to have played a role in the attack on the US mission that killed four Americans, including Ambassador J. Christopher Stevens. Militants have also attacked other foreign targets recently, including an attempted ambush of Italy’s consul this month.
Britain’s Foreign Office also warned against ‘‘all but essential travel’’ to several other Libyan cities besides Benghazi, citing a ‘‘high threat from terrorism’’ and a possibility of retaliatory attacks targeting Western interests in the region after the French military intervention in Mali, which preceded last week’s Islamist militant attack on a remote Algerian gas field near the Libyan border.
This week, a senior Algerian official said several Egyptian members of the squad that attacked the Algerian gas complex were also among those who had attacked the US mission in Benghazi.
The Egyptians were among 29 kidnappers killed by Algerian forces during the four-day siege of the gas plant, in which at least 37 foreign hostages and one Algerian died. Three militants were captured alive and one of them, under interrogation by Algerian security forces, recounted the Egyptians’ involvement in both attacks, the Algerian official said.
“We are aware of a specific, imminent threat to Westerners in Benghazi,’’ the Foreign Office advisory said. ‘‘We advise against all travel to Benghazi and urge any British nationals who are there against our advice to leave immediately.’’
The advisory also recommended that Britons who were still in Benghazi travel only in groups and only during daylight hours.
In other Libyan places, it said, ‘‘there is a high threat from terrorism. Attacks could be indiscriminate, including in places frequented by expatriates and foreign travelers.’’