Story highlights The embassy urges citizens to consider deferring travel

Kenya has sent troops across the border into Somalia to pursue suspected Islamic militants

Recent abductions of tourists and aid workers in Kenya have heightened tensions

The U.S. Embassy in Kenya warned it has credible information of an imminent terror attack, days after the east African nation announced it is sending troops to Somalia to battle Islamist militants.

The attack is likely to target places that foreigners congregate in Kenya, including malls and night clubs, the embassy said.

The U.S.Embassy did not offer details on who might carry out such an attack, but said it has taken measures to limit official U.S. government visits. It urged its citizens to consider deferring travel to Kenya.

The warning comes after Kenya sent troops across the border into Somalia to pursue Islamist Al-Shabaab militants. The terror group has threatened Kenya with retaliatory attacks, saying it considers the forces' incursion an affront to Somalia's sovereignty.

Al-Shabaab, which is linked to al Qaeda and has been designated a terrorist organization by the United States, is fighting to impose its own interpretation of Islamic law, or sharia, on Somalia.

Kenya has blamed some recent abductions of tourists and aid workers on the terror group, which has heightened tensions.

On September 11, armed bandits broke into a beachfront cottage where Britons Judith and David Tebbutt, both in their 50s, were staying. David Tebbutt was shot dead while trying to resist the attack. His wife was grabbed and spirited away on a speedboat, and is believed to have been taken into Somalia.

On October 1, pirates made another cross-border raid, this time snatching a French woman in her 60s, who used a wheelchair and was believed to be in bad health, from a holiday home on Manda Island where she lived part of the year. She later died, likely because of the kidnappers' refusal to give her medicine, according to the French Foreign Ministry.

Also this month, gunmen abducted two Spanish workers from the medical charity Doctors Without Borders from the Dadaab refugee complex, about 80 kilometers (about 50 miles) from the Somali border.

Al-Shabaab has denied responsibility for the abductions.