Hot and dry conditions have Ottawa firefighters anticipating a busy stretch that began with a brush fire south of Ottawa on Wednesday.

Firefighters carried backpacks of water while riding all-terrain vehicles to the brush where 10 acres were burnt. (Ashley Burke/CBC)

Firefighters returned this morning with reinforcements to an area in the Marlborough Forest near the intersection of Roger Stevens Drive and Dwyer Hill Road. They continue to monitor hot spots to ensure the fire does not start up again.

The brush fire was first noticed Wednesday afternoon by a passing aircraft. All-terrain vehicles, an off-road firefighting vehicle and 25 firefighters responded along with a Ministry of Natural Resources helicopter.

About 10 acres in all were consumed by the blaze, which firefighters had a difficult time accessing. The brush is now easier to access after construction crews bulldozed a trail into the bush.

Firefighters discovered marijuana plants while fighting the fire, said fire department spokesman Marc Messier. Police were called to the scene.

Police said it's common for marijuana plants to be planted on public land, because it's harder to prove who planted them.

Don't discard lit cigarettes, matches

Nobody was injured in the fire.

Firefighters continue to stay at the scene as a precaution.

The dry conditions have fire officials warning people not to discard lit cigarettes or matches, which could cause brush fires.

Firefighters have responded to "numerous calls" over the past few weeks for smouldering mulch at homes and businesses caused by improperly discarded cigarette butts, officials say.

A burn ban is also in effect for Ottawa.