Two people were injured after the vehicle they were travelling in ran over a landmine at Nyongoro along the Garsen-Lamu road.
The suspected Al-Shabaab attack happened at around 6.30am.
Linda Boni Security Operation director Joseph Kanyiri confirmed the Monday attack, saying security personnel were pursuing the attackers.
Coast regional police boss Larry Kieng said: “I confirm a lorry ran over a landmine. No deaths have been reported. More details will follow.”
Lamu County Commissioner Gilbert Kitiyo also confirmed the attack, saying police were on the ground “assessing the situation”.
According to a police source on the ground, there was still an exchange of fire between the attackers and security officers in the area by 9am.
The lorry (a canter) was from Malindi and was heading to Lamu’s Mokowe jetty to collect fish when the incident happened.
The injured have been taken to Witu Dispensary for treatment.
Nyongoro is the same place where a Kipini Raha bus ferrying passengers from Malindi to Kipini was attacked by suspected Al-Shabaab militants last week.
The gunmen opened fire on the vehicle and injured five passengers before police repulsed them.
Three other people on a motorbike were killed in the ambush.
It is also the same place where three Tana River County government officials were killed when their RAV 4 vehicle was sprayed with bullets before the militants set the vehicle alight.
The vehicle’s occupants were burned to death in the horror attack.