Afghan police boosted their presence on Kabul's streets and erected new checkpoints Thursday as the new US envoy to Afghanistan and Pakistan, Richard Holbrooke, arrived, dpa reported.
The beefing up of the security also came a day after eight Taliban suicide bombers breached the city's defences in near-simultaneous attacks on three government buildings that left 26 people dead.
Holbrooke is on a fact-finding tour to discuss strategies with Pakistani and Afghan leaders in the fight against the resurgent Taliban.
Holbrooke was scheduled to hold informal meetings on Friday before seeing Afghan President Hamid Karzai on Saturday, Foreign Ministry spokesman Sultan Ahmad Baheen said.
Holbrooke visited Islamabad earlier in the week and was expected to continue his regional trip to India next week.
Meanwhile, in southeastern province of Paktika, a Taliban suicide bomber attacked a police headquarters on Thursday morning, killing one police officer and wounding 10, while a soldier died in a similar attack in southwestern Nimruz province.
In Kabul, Karzai chaired a meeting at the presidential palace with the defence, interior and intelligence chiefs to evaluate the recent attacks in Kabul.
The president instructed the security chiefs to use all their "abilities and possibilities," in order to prevent a repeat of Wednesday's "terrorist attacks" a statement released by the president's office said.
The new security measures in the capital came a day after Interior Minister Hanif Atmar admitted the "enemy still has the ability to transport weapons and explosives into Kabul city."
Atmar said the government would take "tougher security measures" but did not give details, other than warning they would cause more disruptions to daily life.
Wednesday's attacks were sanctioned directly by Taliban supreme leader Mullah Mohammad Omar and were conducted by eight suicide bombers equipped with assault rifles, the Taliban said in a statement posted on its website.
It said the attack was carried out to avenge the execution of some of the group's members in government prisons last year. Another eight attackers returned to their bases after the attacks, the statement said.
The deadliest attack was carried out by five assailants who stormed the Justice Ministry, opening fire on employees "indiscriminately" and tossing hand grenades. All five were killed in a three-hour gunbattle with security forces.
The sixth bomber was killed before he could attack the Education Ministry while the last two members of the group attacked the prisons directorate.
The attacks killed at least 26 people - most of them civilians, but also police and intelligence officers.
Amerullah Saleh, head of the intelligence department, said the attacks were masterminded by militants based in Pakistan. He said his agency was looking for 21 suspects.
Afghan officials have repeatedly said insurgents get training and equipment from backers hiding in the tribal areas of Pakistan, close to the porous Afghan border.
The attacks raised concerns among war-weary Kabul residents, who have recently seen a series of suicide attacks in the city protected by thousands of Afghan and international troops.
"Yesterday's attacks really reminded me of the country's civil war," Ahmad Munir, 34, a shopkeeper, said Thursday, referring to the war fought in the 1990s among mujahedin factions after the ouster of Afghanistan's Soviet-backed regime.
"Like that time, the city's streets suddenly were deserted and people were really horrified," he said.
"The people are very worried because they see the Taliban have become so powerful that they can attack a government ministry to seek revenge for the deaths of their comrades," said Waheed Muzhda, a political analyst and a Foreign Ministry official during the Taliban regime.
Afghan and NATO military officials have predicted a tougher 2009 than the previous year. Last year was the deadliest for the war- wracked country since the ouster of Taliban regime seven years ago.
Under the new US policy and its change of attention from the Iraq war to Afghanistan, up to 30,000 additional US soldiers were expected to be sent to the country in the next 18 months.