Kenyan anti-terror police have detained two Iranian men using forged Israeli passports to enter the East African country, on suspicion that they may have been involved in a plan to carry out an attack there, officials said on Friday.

Kenyan security agencies have been on alert following several gun and grenade attacks and the killing of 67 people in an attack by Islamist gunmen on Nairobi's Westgate shopping mall last September.

Mwenda Njoka, spokesman for the Ministry of Interior and Coordination of National Government, said the two Iranians had passports identifying them as Israeli nationals and had tried to enter Kenya through its main airport on Thursday.

"The Iranians are suspected to be terrorists, either coming here as their final destination or in transit to another destination. The matter is being handled by the anti-terror police and Interpol," Njoka told Reuters.

The two were taken to court but did not enter a plea pending further investigations by the National Intelligence Service and the Anti-Terrorism Police Unit (ATPU), he said.

It was not immediately clear if they would face charges. 

Nearly a year after the Nairobi shopping mall attack, police say they have tightened security at entry points to the country.

Kenya's tourism industry has been hit hard by the attacks. Some Western nations have warned their citizens against traveling to parts of Kenya, including its coastal resorts, prompting mass cancellations.

Kenya last week swore in Major-General Philip Kameru as its new intelligence chief. He is tasked with tackling the rising threat from Somali Islamist militants al Shabaab, who are thought to be bent on retaliation after U.S. missiles killed their leader Ahmed Godane.

Including the Westgate shopping mall attack last September, there have been 65 reported terrorist incidents across Kenya in the last 12 months, resulting in 261 deaths and 486 wounded, according to global risk consultancy Maplecroft.

Two Iranian men were sentenced to life in prison by a Kenyan court in May last year for planning to carry out bombings in Nairobi and other cities. They have appealed their sentence.

The two were found guilty of planning attacks and possessing 15 kg (33 lb) of explosives. Kenyan investigators said at the time it was unclear whether they had ties to al Qaeda-linked militants in Somalia or were part of another network.