* Warnings issued after series of attacks
* Tourism already "on its knees" - president
* Officials say visitors safe, know of no imminent threat
NAIROBI, May 15 (Reuters) - Kenya rebuked Britain, the United States, Australia and France on Thursday for issuing warnings about travel to the east African country and particularly its main port city after a series of attacks there.
Kenya called the alerts "unfriendly", saying they would increase panic and play into the hands of those behind the gun and grenade assaults.
Kenya has blamed bomb blasts in the capital Nairobi and the main port city Mombasa this month, as well as other attacks, on the al Qaeda-linked Somali group al Shabaab.
The Islamist movement killed at least 67 people including foreigners in a raid on a Nairobi shopping mall in September, saying it was in revenge for attacks on its fighters by Kenyan troops in Somalia.
The warnings may further damage Kenya's tourism sector, one that President Uhuru Kenyatta said is "on its knees" following the raids in the capital and along the Indian Ocean coastline.
Karanja Kibicho, the principal secretary at the foreign affairs department, said Kenya was assuring its visitors of "utmost security and safety", and lamented the advisories by countries also involved in its fight against the militants.
"The advisories therefore are obviously unfriendly acts coming from our partners who have equally borne the brunt of global terrorism and no doubt understand the repercussions of terror menace," Kibicho said.
"The challenges arising from acts of terrorism require concerted efforts to fight it and not behaving in a manner that accelerates it by causing fear and panic."
Kenyan authorities say they do not know of any imminent threats.
Western diplomats have privately said Kenyan security forces - which receive aid and training from the United States, Britain and Israel among others - are weakened by inter-agency rivalries that hamper intelligence work.
Britain's Foreign Office told its citizens they should avoid travel to Mombasa and the surrounding area because of "recent terrorist attacks and the continuing terrorist threat in the area," unless travel was essential.
The U.S. Embassy warned its citizens of the continued threat of "potential terrorist attacks in the country," citing targets include hotels, nightclubs and malls.
Kenya said Australia and France issued similar warnings. (Reporting by James Macharia; Editing by Edmund Blair and Andrew Heavens)