The two Syrian Arab Red Crescent volunteers and one ICRC staff member were travelling from Aleppo to Idlib when the blast hit their marked vehicles.
A spokesman for the ICRC in Geneva said the aid workers were taken to a medical facility and that their injuries were minor.
Earlier, Syrian forces pushed out scores of rebels holed up in the Haffa region near the Mediterranean coast, with state television claiming they had regained control after eight days of fierce fighting.
The area is only about 20 miles from president Bashar Assad’s hometown of Kardaha in Latakia province, the heartland of the Alawite minority to which Mr Assad and the ruling elite belong.
France has said Syria is already in a civil war, echoing a similar statement by UN peacekeeping chief Herve Ladsous on Tuesday.
The new French foreign minister Laurent Fabius said: “If you can’t call it a civil war, then there are no words to describe it.”
He added that to stop “this civil war from worsening,” Mr Assad must leave power and Syrian opposition groups must start a new government. He said he will be in personal contact with the opposition inside Syria.
Syria’s foreign ministry expressed “astonishment” over Mr Ladsous’ statement and a spokesman insisted security forces were simply battling armed terrorists.
Hundreds of rebel fighters were believed to have been holed up in Haffa villages and pulled out overnight after intense fighting.
In the central city of Homs, Syrian forces fired a continuous rain of shells that slammed into civilian neighbourhoods, but rebels were still clinging to the area.
Meanwhile, Assad’s backer Russia’s has denied a claim by US Secretary of State Hillary Clinton that Moscow is sending attack helicopters to Syria. Foreign minister Sergey Lavrov insisted during a visit to Iran that Russia is only completing earlier weapons contracts for air defence systems.