There is a manhunt under way in Kenya for an al-Qaeda operative wanted for the attacks on the US embassies in Kenya and Tanzania 10 years ago.
Fazul Abdullah Mohammed allegedly evaded a police raid at the weekend in the coastal town of Malindi, where he was being hosted by friends.
Earlier this year the suspect, who is from the Comoros Islands, survived a US missile attack on a hideout in Somalia
The United States has offered a reward of up to $5m (£2.5m) for his arrest.
Three people arrested over the weekend - reportedly relatives of Mr Mohammed - pleaded not guilty on Monday to accusations they had harboured him.
A judge ordered that they be held for four more days while prosecutors gather information.
Meanwhile, the man who led the investigation into the Kenya bombing, Maj Marsden Madoka, has told the BBC's African Perspective programme that Kenyan intelligence passed on information to the US embassy ahead of the attack in 1998, but it was not acted on.
The failure may have been due to a lack of communication between the embassy and US intelligence agencies, he said.
More than 250 people were killed in the bomb attacks 10 years ago that Mr Mohammed allegedly planned.
The BBC's Odhiambo Joseph in Mombasa says police and naval patrols have been intensified at the coast after the failed arrest bid at the weekend.
In neighbouring Uganda, the US embassy has warned that Americans in East Africa may be at heightened risk from attack ahead of Thursday's tenth anniversary of the bombings.
Reports say Mr Mohammed gained entry to Kenya through Lamu Island which borders Somalia to seek treatment for a kidney ailment, our correspondent says.
Mr Mohammed allegedly leads the al-Qaeda cell in East Africa from a base in lawless Somalia.
The US accused the Islamist group that ruled much of southern Somalia in 2006 of harbouring al-Qaeda suspects - charges they denied.
Mr Mohammed joined al-Qaeda in Afghanistan and trained there with Osama bin Laden, the terror network's leader, according to the transcript of an FBI interrogation of a known associate.
As well as the embassy bombings, he is also suspected of planning the car bombing of a beach resort in Kenya and a near simultaneous attempt to shoot down an Israeli aircraft in 2002.