Canada has become the first nation to admit publicly it is worried about travelling to the World Cross Country Championships this weekend after the upsurge in terrorist violence in Northern Ireland.

"The Canadian team has some serious concerns with regards to recent incidents in Belfast," said Marek Jedrzejekcheck, the head coach. "Safety is the number one concern for Canadian athletes competing in Belfast." Last week solicitor Rosemary Nelson was killed by a car bomb in Lurgan, while on Wednesday, dissident Loyalist Frankie Currie was shot dead on the Shankill Road.

More than 800 athletes from 67 countries are due to travel to Belfast for the championships, the first major event to be held in Northern Ireland since the Open Golf Championship in 1961.

Tension is likely to be high this weekend as the first anniversary of the Good Friday peace agreement approaches and crucial talks on weapons decommissioning take place.

Although the event's organisers are aware that many athletes have concerns about visiting Belfast, they reiterated yesterday that there were no grounds for alarm and that security will be tight for the races on Saturday and Sunday.

"While it's perfectly understandable to have concerns, we can reassure all teams that, as in any event of this magnitude, all possible precautionary measures have been taken," said Noel Munnis, the event's manager.