A senior official of Kenya's anti-terrorism police unit said the country remained at risk of attacks despite increased security.
"Kenya has always been a target for terror attacks and we have really learnt a lot, we are on high alert," said the official who requested not to be named.
Ceremonies in Nairobi and Dar es Salaam commemorated the victims of the August 7, 1998 bombings, which killed a total of 224 people and injured some 5,000, almost all of them Africans.
'Susceptible to terror'
Ten years on, many of those responsible for the attacks, and the bombing of a hotel in Mombasa in 2002, "remain at large and continue to operate in the region", and Kenya "remains potentially susceptible to attacks from terrorists in the region", the US says.
Past memorials have been low key with many victims protesting lack of compensation for their loss.
At Nairobi's memorial park, site of the former US embassy where 213 people, including 12 Americans and 34 local embassy staff died in the 1998 attack, survivors lamented a lack of continued support by the Kenyan and American governments.
"This being the tenth year, nothing has changed in that there is no support from so many angles, the Kenyan government, the American government," said Paul Wala, the head of a victims association.
"We blame them [the US] for the bombing. Without their embassy being here in Kenya we would not have been bombed," he told the AFP news agency.
"Many have died from the injuries, many have died because they don't have medical support, many have died because they cannot meet their obligations," said Douglas Sidialo, 38, now blind following injuries sustained during the blast.
Washington says it has already spent about $42m in medical treatment, school fees, counselling and reconstruction services for the thousands of Kenyan and Tanzanian victims and is reluctant to pay out more.