U.S. citizens in Afghanistan can expect to be the target of "multiple imminent attacks," the U.S. Embassy in Kabul announced in a statement on Tuesday.
The statement added that they lacked specifics on "the timing, target, location, or method of any planned attacks."
"As of late February 2015, militants planned to conduct multiple imminent attacks against an unspecified target or targets in Kabul City, Afghanistan," the statement reads.
Security in the country continues to be tenuous at best after the U.S. officially ended its war there in December.
In addition to the ongoing threat of Taliban militants, the country's former brutal Islamic extremist rulers, it is believed the Islamic State of Iraq and Syria (ISIS) has begun operating widely in the country's south.
Afghan officials only confirmed in January that ISIS was operating in southern parts of the country. The following month, a drone strike killed the top recruiter for ISIS in Afghanistan, according to local officials, marking the first such attack on the extremist group in a volatile country where it has a small but growing following.
Gunmen in southern Afghanistan kidnapped 30 members of the Hazara ethnic community, authorities said Tuesday, in what appeared to be the latest in a series of attacks on Shiites in the predominantly Sunni country.
No group immediately claimed responsibility for the attack Monday afternoon, police and officials said.
The gunmen kidnapped the 30 people, all men, from two vehicles on a major road in Zabul province, provincial Gov. Mohammad Ashraf said. He said all women, children and non-Hazaras were left behind.
Authorities were searching for those kidnapped, some of whom may be government officials, Ashraf said.
Abdul Khaliq Ayubi, a local government official, said the gunmen all wore black clothing and black masks.
The Interior Ministry said the buses were traveling from the southern city of Kandahar to the capital Kabul when the kidnapping was carried out by "unknown armed individuals."
The Hazara, who account for as much as 25 percent of Afghanistan's population, are mainly Shiite. The group has been targeted by the Taliban and other Sunni extremists, who view Shiites as apostates.
The predominantly ethnic Pashtun and Sunni Taliban persecuted the Hazara minority during their 1996-2001 rule, when they imposed a harsh version of Islamic law on the country.