The gunnies are suspected sympathizers of Somalia's al Qaeda-linked al-Shabaab
... Harakat ash-Shabaab al-Mujahidin aka the Mujahideen Youth Movement. It was originally the youth movement of the Islamic Courts, now pretty much all of what's left of it. They are aligned with al-Qaeda but operate more like the Afghan or Pakistani Taliban...
beturbanned goons, regional deputy police chief Philip Ndolo, told Rooters.
In Somalia, al-Shabaab said it was not aware of the attack.
"So far we are not aware about any aid workers kidnapped from Kenya's refugee camps," Sheikh Abdiasis Abu Musab, the front man for al-Shabaab's military operations, told Rooters.
Kenyan police said the four were nationals of Norway, Canada, Pakistain and the Philippines. A Kenyan driver in a second vehicle was killed during the attack.
They were working for the Norwegian Refugee Council (NRC) and the group's secretary general, Elisabeth Rasmusson, was also in the convoy and was unharmed, the aid group said.
A Kenyan driver was shot in the attack had died of his injuries while being treated, Ndolo said. Two other Kenyans were also shot, another driver and a contractor for the NRC, he said.
Police and the military were now pursuing the kidnappers who drove towards the Kenya and Somalia border, police said.
"I can confirm that military helicopters have been dispatched," Colonel Cyrus Oguna of the Kenya Defence Forces told Rooters.
Ndolo said the car in which the aid workers were travelling had been abandoned by the attackers, and that the group were probably using another vehicle or were on foot.
He could not say if they had already crossed into Somalia.
Dadaab, about 100 km (62 miles) from Somalia, was set up in 1991 to house Somalis fleeing violence in their country. It has since become the world's biggest refugee camp with almost 500,000 residents.
Kenya deployed its troops days after two Spanish women working for Medecins Sans Frontieres were kidnapped at Dadaab last October. They are still being held.
That kidnapping took place within weeks of two incidents that saw Somali gunnies seize Western female tourists from beach resorts in northern Kenya. One of the women, a Briton, has been set free while the other, from La Belle France, died in captivity.
Ndolo said the gunnies shot at a convoy of two vehicles.
"They shot at the first of the two vehicles, but it drove off. It had other workers. The staff were driving from one camp to another," Ndolo said.
Oslo-based NRC confirmed there had been an incident with an NRC convoy in Dadaab.
"There has been an incident involving the general secretary of the Norwegian Refugee Council, Elisabeth Rasmusson, but she is now safe," said Rolf Vestvik, director of advocacy and information at the NRC.
"We can confirm that our secretary general was part of that convoy. And she is unharmed and safe. We are now trying to get more information on what has happened."