The bomb attack on Derry's Everglades Hotel could hit plans for the Walled City Marathon this weekend.
The reception area of the hotel was badly damaged in an explosion earlier this morning.
Police said a man threw a device into the reception area of the Everglades Hotel at 11.15pm last night.
The hotel was evacuated and a bomb disposal team was sent to the hotel.
However, police said that while they were working on the device it exploded around 2am.
No one was injured as a result of the explosion.
A burnt out car found a short time later at Foyle Road in Derry is believed to be linked to the hotel attack.
It is clear from the scene this morning that extensive damage has been caused to the reception area.
A PSNI spokesperson this morning praised the quick actions of the hotel staff in evacuating the building and raising the alarm.
No organisation has claimed responsibility for the hotel attack.
The Everglades Hotel hosted a recruitment event for the PSNI on May 22 and was due to host a similar event next week.
The Walled City Marathon is due to start at the Everglades Hotel on Sunday morning.
Around 1,500 runners are due to take part in the race.
The main ballroom in the hotel was to be used by runners preparing for the marathon.
It is not yet clear what impact this morning's explosion will have on the start of the marathon.
DUP councillor Gary Middleton, who was at the scene at the Everglades during this morning's alert, said around 30 rooms were occupied in the Everglades Hotel last night.
Among the guests evacuated were people who had travelled to Derry for a funeral.
Alderman Middleton said the Everglades guests were taken to the City Hotel following the evacuation.
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