|A plaque with the names of those|
killed in 1998 bombings, most of
The officer, who requested anonymity, said the people were detained last night in Eastleigh residential district in the city's northeast subsurb.
The district is mostly inhabited by Kenyan Somalis and refugees from Somalia.
It is notorious for harbouring criminals.
The official did not give details of the arrests saying, "It is a bit too early to comment on that."
On Friday, the US embassy shut down after receiving intelligence information of a serious "terror" threat.
“The information that is available to us and to Kenya indicates that there is a serious terrorist threat in Kenya”, US embassy spokesman Tom Hart said.
But Kenyan National Security Minister Chris Murungaru criticised the US decision, describing it as "wrong and misleading".
US defence officials in Washington said that the Pentagon’s Defence Intelligence Agency had already put its threat level for Kenya on the highest state of alert.
But Kenya’s permanent secretary in charge of security Dave Mwangi said he was unaware of a new specific threat.
“Unless (the United States) have any information I do not have, I don’t think there is anything new”, Mwangi said.
Five years ago, explosions targeting US embassies in Nairobi and the Tanzanian capital Dar as-Salam, killed 224 people, most of them Africans.
The Nairobi embassy was later rebuilt on a site outside the city.
Citing intelligence reports, a US official said al-Qaeda was plotting attacks in Kenya.
“What’s going on today is continued concerns about threat information that indicates al-Qaeda operatives are continuing to plan and could undertake an operation at any time”, said the official who requested anonymity.
He added that the State Department had warned last month that US facilities in the region were in danger of “imminent” attack.
US State Department spokesman, Philip Reeker, said the embassy would be shut down at least until Tuesday.
“We do not expect that the embassy… will remain closed Monday and Tuesday, but obviously we’ll keep you current on that as the weekend goes by and those days arrive”, Reeker declared.
Last month, the State Department cautioned US citizens against traveling to east Africa, including Kenya, saying there was a threat of using shoulder-fired missiles on aircraft.
The State Department also authorised family members and non-emergency personnel at the US embassy in Nairobi to leave after warnings of possible attacks.
Washington has been closing embassies across Africa, periodically since 1998, citing security reasons.
Decisions to close down embassies increased after the 11 September 2001 attacks.
Al-Qaeda claimed responsibility for an attack on an Israeli hotel in Kenya that killed 16 people in November 2002.
The attack was followed by a failed attempt to shoot down a civilian plane by shoulder-fired missiles at a nearby airport.
Fearing damage to its tourist industry, Kenya has asked the United States and Britain to lift their travel warnings against the east African country.
Kenyan officials say authorities are providing sufficient security to deal with a threat of another attack.
But the United States says Kenyan authorities have failed to capture any suspects involved in the November 2002 attacks and therefore, the threat of an attack in Kenya continues.