Security forces in Bahrain are investigating an explosion that rocked the kingdom on the last day of the Formula One motor racing Grand Prix.
On Sunday, three witnesses reported hearing a blast in the bustling Aliya district of the capital Manama, where many foreigners live.
The Interior Ministry on Monday confirmed the blast, saying on its official Twitter account that it was investigating the incident.
There were no reports of casualties. Police blocked the road where the incident took place near a government security building.
Though caught up in political turmoil, the authorities in Bahrain see the Grand Prix as a way to raise the kingdom's international profile and attract tourists and foreign investment.
In 2011, when the unrest first broke out as part of the Arab Spring, the race had to be cancelled.
Unrest in the run-up to the race, staged about 30km south of Manama at the Sakhir desert circuit, was markedly lower than in the past two years, apparently due to a more effective security clampdown on Shia villages.
Many Bahraini Shia complain of discrimination, especially in employment and housing, a charge that the Sunni government denies.
Political reconciliation talks between the government and opposition have made little progress.
Earlier on Sunday, a small crowd of youths in the Shia village of al-Eker, south of Manama, burned tyres and threw stones at police who responded by firing tear gas, according to Reuters news agency. The youths quickly dispersed.
On Friday, tens of thousands of mainly Shia protesters marched for democratic reforms.