NAIROBI - Kenyan leaders on Sunday condemned grenade attacks in Nairobi that have so far claimed six lives and wounded 63 others still being hospitalized.

Speaking separately, Vice President Kalonzo Musyoka and National Security Minister Professor George Saitoti condemned the cowardly attack that was carried out at the Country Bus Terminus popularly known as Machakos Airport by terrorists.

Musyoka said such attacks will not break the Kenya's resolve to guarantee security to its citizens. He assured that Kenyans will continue to fight terror until those elements that are bent on disrupting peace in the country are defeated.

"We will be more committed to fighting terror. We will not allow terrorists any room in our country," Musyoka said on Sunday at Kenyatta National Hospital (KNH) after he visited to condole with the victims and families of those who were injured in the attacks.

Traces of blood, strewn bags and shoes were still visible on the floor of the bus station, where around several buses were still parked, and ambulances were still ferrying the wounded to hospital.

The police have since sealed off the areas as investigation is underway to establish the motive of those behind the attacks.

National Security Minister Saitoti on his part blamed the Saturday grenade attack on a Nairobi bus station killed at least six people and wounded 63 on Al-Shabaab who the Kenya Defense Forces are battling in southern Somalia.

"The death toll is now six, and we have 63 people undergoing treatment at the Kenyatta National Hospital, 11 of them were seriously injured," the minister told a news conference in Nairobi on Sunday.

"The initial suspicion is that of Al-Shabaab, but we want to make sure that once we finalize the investigation, we come out very clearly and give the information. Undoubtedly, these attacks are very similar to the previous explosions we have seen," he said.

Three people died on the spot after occupants in a speeding vehicle hurled grenade in the middle commuters who were waiting to board upcountry buses to various destinations across the country.

Saitoti said the investigation is underway at the site of the attack and that surveillance has been stepped up in all public places including churches, shopping malls and bus termini.

"I appeal to all law abiding citizens to remain vigilant in identifying and reporting any suspicious characters to the police, " he warned.

The minister said security agencies are pursuing leads to have the suspects behind the heinous act to face justice.

"Unknown people in a vehicle driving along Landhies Road towards Jogoo Road threw four grenades consecutively about seven meters apart. As a result, one person died on the spot while five succumbed to injuries at Kenyatta National Hospital," Saitoti said.

Speaking at the hospital, Musyoka called on Kenyans to remain calm as the security agencies were doing everything possible to bring the culprits to book.

At the same time, the Vice President called upon nurses to assist their Kenyan brothers and sisters who need urgent medical attention.

Musyoka said although nurses were on strike there was urgent need for them to provide the services that needy Kenyans require.

The Vice President who was accompanied by Dr. Simeon Monda of KNH and other dignitaries, commended KNH staff and other rescue agencies for their rapid response in saving the lives of Kenyans.

"This is an act of people who think that they can puncture the resolve to fight terror, it is a difficult moment by it should strengthen our resolve and am sure we will win," said the vice president.

Al-Shabaab was responsible for a string of tourist abductions and grenade attacks that occurred late last year that led to the Kenyan troops' pursuit of the militia group into Somalia.

The internal security minister denounced the recruitment of Kenyans into the Somalia-based militia group and further pled with any individuals with vital information on such criminals to come forward.

The Country Bus Station, near the city center and next to one of the largest markets in Nairobi, is usually a popular bus terminus with passengers boarding buses to up country destinations and others arriving.

The Saturday night incident is the third to rock Nairobi since Kenya launched military action in Somalia to battle Al-Shabaab militia in October last year.

The incident also comes amid heightened security in Nairobi after Somali insurgents threatened reprisal attacks in Kenya if the KDF troops do not leave the Horn of Africa nation.

Since the military action started,  the East African nation has also been beset by a spate of grenade and landmine attacks in its northern region where the insurgents have killed more than ten police officers and over 30 civilians.

Several of them believed to have been carried out by Al-Shabaab have occurred in Mandera, Wajir, and Garissa and Dadaab districts even as the military reports gains against the Islamist group by capturing their military bases and killing scores of them.