NAIROBI - Gunmen kidnapped four aid workers and killed a driver at Kenya's Dadaab refugee camp near the border with Somalia on Friday, in the first kidnapping of foreigners since Kenya sent troops into Somalia in October to try to crush Islamist militants.

The gunmen are suspected sympathisers of Somalia's al Qaeda-linked al Shabaab insurgents, regional deputy police chief Philip Ndolo, told Reuters.

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 spokesman for al Shabaab's military operations, told Reuters.

Kenyan police said the four were nationals of Norway, Canada, Pakistan and the Philippines.

A Kenyan driver in a second vehicle was killed during the attack.