Road casualty figures dropped last year to the lowest overall level since records were first collected almost 90 years ago, according to government statistics, but deaths and injuries among cyclists bucked the trend by rising sharply.

Cycling groups are demanding urgent government action to stem the casualty numbers, which are going up more quickly than the increase in riders on the road. Cyclist deaths rose 10% during 2012, with serious injuries up by 4%, the latter increasing for the eighth consecutive year.

It is the only area where road casualties are rising, aside from a small increase in the number of seriously injured pedestrians, another vulnerable group.

The Department for Transport (DfT) statistics show that the total number of road deaths fell 8% year-on-year to 1,754, the lowest since such figures were first collected in 1926. Serious injuries fell by 0.4%, and remain 15% lower than the 2005-9 average.

At 145,571, the number of recorded road accidents in which someone was injured was lower than in any years other than 1926 and 1927, despite the vastly greater number of vehicles in use now.

This was reflected in reduced casualty numbers for just about every road user. Among motorcyclists there was a 9% drop in deaths and 5% decline in serious injuries.

In contrast, the number of cyclists killed on the roads rose from 107 in 2011 to 118 last year, with serious injuries rising to 3,222.

The number of cyclists on the roads has increased in recent years, particularly in some cities, but campaign groups argue that the rise in the number of deaths and injuries has been proportionately greater.

The DfT report also notes that 2012's unusually wet spring and summer – the April to June period was the second rainiest on record – is likely to have pushed down casualty figures for cyclists, pedestrians and motorcyclists, as people chose other transport options in the wet.

British Cycling said the statistics were very disturbing. Its policy director, Martin Gibbs, said: "Although the number of people cycling is increasing, the number of casualties is increasing at an even faster rate. If the government is serious about getting Britain cycling we need to ensure that cycling is built in to all new road developments and junctions."

Jason Torrance, the policy director of Sustrans, said: "The 118 people who died riding a bike on our roads this year have died needlessly and must surely spur the government into immediate action to make our roads safer.

"It is unacceptable that seriously injured cyclist casualties have increased eight years running. The safety of cyclists must be included at the heart of the design of our roads as a requirement of all future schemes and a review of the safety of cyclists using existing roads must take place."

The increase in cycling casualties has baffled many campaigners, particularly given the generally observed "safety in numbers" effect in which more cyclists on the roads tends to make riding safer overall. Studies have shown that risky or illegal behaviour by cyclists is rarely the cause of serious accidents.

In April an all-party group of MPs released a report on how to boost the number of Britons cycling, spelling out a series of specific recommendations on segregated lanes and other safety infrastructure. The government has not said whether it supports such moves.