Tension is high in Kenya's northern border town of Wajir amid a major security operation to arrest those behind two grenade explosions that wounded four people.

Wajir Divisional police commander James Mutungi said they have launched investigations in the two grenades which occurred on Monday night and early Tuesday.

"We are yet to make arrests but a major manhunt is underway to apprehend the attackers," Mutungi told Xinhua on Tuesday.

The attacks which are linked to the ongoing inter-clan killings in the area, came even as President Kenyatta warned the government will use force to restore peace in Wajir and Mandera Counties if the fighting there continues.

Residents including security officers interviewed said the attacks hurled a grenade at a crowd and escaped, an incident that has sparked tension in the restive town.

Residents said on Tuesday tension continued mount in the area as two people are reported to have been killed in Wajir on Monday after they were hit by a vehicle in a commotion where a group of rowdy crowd started throwing stones at vehicles being used to ferry internally displaced persons to Mandera under tight security.

Police were forced to shoot in the air to scare away the crowd. Some of the more than 20 who were injured in attacks on Sunday were flown to Nairobi yesterday for treatment, officials said.

Mutungi said that the four who were wounded when unknown persons hurled grenade at where they had seated outside a shop near Baraza Park at about 8:00 p.m. local time on Monday.

The four who were seriously injured are currently admitted at the local hospital where they are receiving treatment.

The local police commander said a second explosion occurred on Tuesday morning targeting police investigating the earlier incident. No one was injured in the second explosion that happened near the shop.

"Its clear that the second explosion was targeting our police officers who were conducting investigation into the earlier one, thank God nobody was there when it exploded otherwise we could be talking of a different story had it exploded on people," said Mutungi.

The incident which overwhelmed the already stretched policemen prompted the authorities to call for the quick intervention of the military personnel as the authorities tried to restore sanity.

The eight lorries which had all their windows smashed in and their occupants were driven to the Wajir police station where they are currently being guarded under tight security.

"The two explosions coupled with the inter clan clashes have led to tension in the town with many residents opting to remain indoors as police patrol the town," said a local who identified himself as Ibrahim Abdi.

The incidences come as President Kenyatta warned of stern action against perpetrators of hostilities in Mandera and Wajir which has fueled hostilities between the Garreh and Degodia clans.

"If the hostilities do not end, we will have no otherwise but to move in with full force," President Kenyatta said in Nairobi when he met political leaders from Mandera and Wajir to discuss the conflict between the Garreh and Degodia clans.

He said his government will engage the Ethiopian government to ensure the peaceful co-existence of all communities along the common border, adding that the killings of innocent children, women and the elderly cannot be tolerated.

In 2008 the government was forced to use the military to quell bloody clashes that claimed more than 40 people and displaced thousands of other in Mandera-East district residents.

The two clans, who both have clan presences in the bordering Ethiopian region, are accusing each other of hiring militias across the border to be engaged in the killings.

The Kenyan leader's warning comes as the death toll from Sunday's grenade attack in northern Kenyan county of Mandera rose to 16 and seven others are still in critical condition.