Gunmen separately shot dead two prominent Nairobi contractors in mystery circumstances.

The first victim was killed in Saika estate on Wednesday night while the second was shot in Kariobangi South yesterday morning.

Police have not established the motive of the killings but have launched investigations.

In the Wednesday incident, the victim was waiting in his car for his gate to be opened when three men emerged from the darkness and pumped bullets into his chest.

Police suspect the victim hesitated to open his door, which prompted the thugs to kill him. They later emptied his pockets and left his lifeless body at the scene.

In the Kariobangi incident, the killers escaped without stealing anything from the victim, whom they shot as he walked to his car

No arrests have been made.

Elsewhere, a gang hijacked a lorry carrying beer, which they emptied before abandoning the vehicle in the city's Ruai estate.

The lorry was ferrying the drinks to Kangundo during the Wednesday night incident.

Kayole deputy Officer Commanding Police Division, Mr Joseph Tonui, said they were hunting for the thugs.

In a similar incident, gangsters drove off in three lorries carrying transit goods on the Nairobi-Mombasa highway.

The lorries, headed for Nairobi, were ferrying production goods for a multinational company when they were hijacked near Emali.

Police are looking for the lorries, believed to be hidden in Nairobi. The incident came days after two other trucks belonging to the Sameer Group were hijacked and thousands of tyres they were carrying stolen.

Police later recovered the tyres and arrested one suspect. Highway hijackings involving long distance trucks and buses are on the rise.

At least 30 vehicles have been attacked in the last month on the Mombasa-Nairobi Nakuru-Eldoret and Kisumu routes.