SANAA //Two US military transport aircraft evacuated American citizens from Yemen yesterday after Washington ordered non-essential embassy staff to leave the country over heightened terrorism threats.
The US state department also urged its other citizens to leave the country "immediately", while the British foreign office said it had withdrawn its diplomatic personnel from Sanaa.
The evacuation came just hours after two US drone strikes killed four suspected Al Qaeda militants in eastern Yemen. It was not clear if the attacks were related to the security alert.
The US embassy in Yemen is among nearly two dozen US missions ordered to be closed across the Middle East, Africa and as far afield as Bangladesh.
The order came after US intelligence agencies intercepted a message from Al Qaeda's chief ordering its offshoot in Yemen, Al Qaeda in the Arabian Peninsula (Aqap), to carry out an attack.
A senior Yemeni interior ministry official said yesterday that a number of Al Qaeda operatives had infiltrated Sanaa over the previous three days, and that security forces were on high alert across the city.
Military helicopters were seen patrolling the skies of the Yemeni capital yesterday, mainly above the US embassy and the city's airport. Later in the day US drones were reported hovering over the city, prompting many Sanaa residents to stay indoors.
"I forced my children in the house and kept them there. Drones in Yemen have a history of killing civilians," said Mohammed Hashem, an accountant.
The Yemeni government on Monday released the names of 25 wanted Aqap suspects, saying they were planning terrorist attacks in the capital and other major cities across the country. The statement said the government would award anyone the equivalent of US$23,000 (Dh84,500) for any information leading to their capture.
US officials have been reluctant to discuss the specifics of the intelligence that led to its embassy closings and the evacuation from Yemen. But US newspaper group McClatchy reported on Monday that intelligence agencies intercepted communications between Al Qaeda leader Ayman Al Zawahiri and his deputy in Yemen, Nasir Al Wuhayshi, the commander of Aqap.
Intercepting conversations between such high-level Al Qaeda operatives is extremely unusual, and policymakers said they had seized on the intelligence to protect American interests.
US lawmakers who were briefed on the threat last week described it as one of the most serious terrorist plots against Americans since the September 11, 2001 attacks. The state department would not confirm how many citizens were flown out of the country, but officials at Sanaa International Airport said that the transport aircraft evacuated about 100 Americans.
Pentagon spokesman George Little confirmed the evacuation and said the US defence department "continues to have personnel on the ground in Yemen to support the US state department and monitor the security situation".
The Yemeni government criticised the evacuation in a statement released by its embassy in Washington which argued that it would serve "the interests of the extremists and undermines the exceptional cooperation" between Yemen and the international community in the fight against terrorism.
The first US drone strike yesterday targeted a vehicle carrying the four militants, while the other targeted a nearby militant hideout. The strikes were the fourth and fifth drone attacks in Yemen in the past two weeks.
Among the four killed yesterday was an Aqap leader Saleh Al Qoti, two local security officials said.
It is unclear if yesterday's drone attacks were directly related to the electronic communications intercepted between Mr Zawahiri and his deputy.
A military attack helicopter was shot down later in the day in the same area, killing the pilot, after the aircraft fired rockets at militants suspected of blowing up oil pipelines, witnesses told Reuters.
Analysts say the latest security scare is indicative of Al Qaeda's evolution in recent years.
As the foreign Arab fighters who made up the core of Al Qaeda in Afghanistan and Pakistan have been decimated by US drone strikes, the network's focus has shifted back to the Arab world, where it has exploited the post-Arab Spring turmoil to find operating space.
Aqap has emerged as the most capable affiliate, launching high-profile attacks against government forces in Yemen and American interests. Most notable was an attempt to bring down an airliner over Detroit on Christmas day in 2009 with a suicide bomber dispatched from Yemen.
Over the past two years the US has launched an aggressive covert military campaign against the group, carrying out dozens of drone strikes and deploying special forces. The Yemeni military has also launched ground operations to push the group back from territory it had controlled in Abyan province.
Wagdi Al Absi, a political analyst and university professor in Sanaa said the Yemeni government had taken nearly every security measure possible in the face of the latest threat.
"This is a major test for the Yemeni government and the only option they have is to succeed," he said.
Some Sanaa residents wondered whether they should venture outside at all in the capital as Ramadan draws to a close.
"Sanaa is not safe anymore. It seems as if we are living in a war zone with military plane above us and soldiers and armoured vehicles everywhere," said Sara Al Ariqi, a local nurse and mother of two.
Traditionally, the last days of Ramadan send shoppers scurrying to stock up on foods and new clothing items for Eid celebrations.
"Its not safe for me and my family and the only option is for us to leave Sanaa until this is all over," Ms Al Ariqi added.
*Taimur Khan reported from New York. With additional reporting from the Associated Press