NAIROBI, Kenya — Somalia’s Islamist extremist rebels, Al Shabaab, threatened Monday to launch suicide attacks in Kenya in retaliation for the Nairobi government's invasion of Somalia in recent days.

Al Shabaab warned of “severe repercussions” if Kenya did not withdraw its soldiers from Somalia.

“Remember what happened in Uganda’s capital,” said Mohamud Ali Rage.

Last year Shabaab suicide bombers killed 76 people in Kampala, Uganda, in an attack the militants said was in response to Uganda sending thousands of troops to defend Somalia’s government as part of an African Union force.

“Your attack to us means your skyscrapers will be destroyed, your tourism will disappear,” said Rage.

Kenya's fear of that its lucrative tourism will be hurt by Al Shabaab's kidnapping and violence is partly behind the Kenyan invasion.

A spate of kidnappings of foreigners in recent weeks has damaged Kenya’s reputation as a safe place to holiday. The first two attacks led to the abduction of foreigners at coastal resorts, and more recently two aid workers were seized from the Dadaab refugee camp.

Kenya has blamed Al Shabaab for the kidnappings and used this as the pretext for sending its troops into Somalia, but most analysts say pirates and criminal gangs are the more likely culprits.

Al Shabaab sent journalists a statement on Monday in which the group denied any involvement in any kidnappings from inside Kenya.

Meanwhile reports from Somalia suggested Kenyan troops were continuing their advance inside the country, approaching the town of Afmadow about half way between the border town of Dhobley and Kismayo, a port town and Shabaab stronghold where suspected U.S. drones strikes have hit training camps in recent weeks.