The US offered on Monday to help hunt down those behind the attacks on Israelis in Kenya, while a statement purporting to be from Al-Qaeda claimed it carried out the assaults on a hotel and airliner.‘‘The fighters of Al Qaeda return to the same place where the Crusader-Jewish coalition was hit four years ago,’’ said the statement posted on the Internet, referring to the bloody 1998 bomb attacks on US Embassies in Nairobi and Dar es Salaam.In Washington, a US official said the statement, signedby the “Political Office of Qaeda al-Jihad” and posted on an Islamist Web site, was being viewed as credible. He added that there was increasing reason to believe that al Qaeda was involved.The official, who spoke on condition of anonymity, said the serial number on the missile fired at an Israeli airliner last week was close in sequence to a missile fired at a US military aircraft in Saudi Arabia last May, suggesting they came from the same batch.Earlier, President Bush offered his condolences to the Kenyan people and offered US assistance in the probe of last Thursday’s attacks.‘‘He (Bush) offered US assistance in their investigation,’’ said White House spokesman Ari Fleischer. ‘‘The leaders shared their commitment to bring to justice those responsible for the attack. The President expressed his appreciation for the cooperation of President Moi and the Kenyan government in the global fight against terrorism,’’ he said.‘‘I would like to assure you that our security and intelligence departments are vigorously pursuing the perpetrators of this crime,’’ Moi said before leaving for the US on Monday. (Reuters)