Saudi Arabia has tightened security amid terror threats mainly to the capital city of Riyadh, state-run media reported on Monday.
According to the Arabic daily Al-Hayat, the heightened security measures cover markets, commercial malls and oil establishments in Riyadh, Xinhua news agency reported.
The interior ministry has received information about an attack targeting a market in Riyadh or an establishment affiliated to the Saudi oil company Aramco.
In Riyadh, two major bombings took place in residential compounds in 2003.
Thirty-nine people died and over 160 were wounded when bombs went off at three compounds in the capital.
In the other attack, a bomb was detonated outside the Al-Mohaya housing compound, west of Riyadh, killing at least 17 people and wounding 122 others.