By Kim Ghattas
BBC correspondent in Riyadh
Saudi Arabia is preparing to host security officials from more than 50 countries and organisations for a four-day counter-terrorism conference.
Saudi Arabia has itself been suffered attacks blamed on al-Qaeda
The gathering starts on Saturday in the capital, Riyadh.
Since May 2003 the kingdom itself has been the scene of a wave of shootings and bombings blamed on al-Qaeda or groups linked to it.
In a city that is already dotted with checkpoints, security has been visibly
stepped up ahead of the conference.
There are more roadblocks, more special forces, more guns seen everywhere.
Hotels where journalists and participants are staying have been surrounded by security barricades.
Cars driving past the buildings have to go through several security checks. And anyone entering the premises is searched thoroughly.
One hotel, where top delegates will stay, is completely off limits.
As part of the ongoing crackdown on militants here, there are also still regular police raids on militant hideouts, and deadly shootouts take place almost every week.
The last thing the Saudis would want is a terrorist attack against the counter-terrorism meeting.
There are several high-ranking security officials attending - including from the US and the UK - and they would be a prime target for Islamist militants in the kingdom, who resent ties between Saudi Arabia and the West.
So the authorities here are taking no risks. But security measures around compounds housing foreigners, or ministries in Riyadh, or even the US consulate in Jeddah, have not been enough to stop attacks in the past.
The militants are getting bolder, and it is likely some of them are looking into how they can disrupt the high-profile gathering.