ISTANBUL (Reuters) - Two car bombs exploded in the Turkish town of Reyhanli near the Syrian border on Saturday, killing four people and injuring 18 others, Turkey's interior minister said. "Two cars exploded in front of the municipality building and the post office in Reyhanli," Muammer Guler told reporters in comments broadcast on Turkish television.

A blast rocked the central Damascus district of Marjeh on Tuesday causing casualties, Syrian state television said, with an AFP correspondent reporting automatic arms fire after the explosion. "Terrorist explosion in Marjeh district of Damascus and preliminary information on casualties," state television reported. The explosion, which state media said also caused damage at the scene, came near an interior ministry building.

The brothers accused of staging the Boston Marathon bombings planned to detonate more explosives in Times Square as they were being hunted by police, New York City officials said Thursday. New York police chief Ray Kelly said the pair intended to use a pressure-cooker bomb -- similar to the two that erupted at the marathon -- as well as five pipe bombs and improvised grenades they still had on hand as they drove around in a hijacked black Mercedes.

US President Barack Obama vowed Thursday that the Boston marathon bombers would be found and held "accountable" as investigators focused their efforts on two potential suspects. "Yes, we will find you, and yes, you will face justice," Obama told a special service in the city, three days after the two bombs killed three people and injured about 180 in a hail of nails and ball bearings. "We will find you, we will hold you accountable," he added in a keynote speech on a special visit to show national solidarity with what he called "one of the world's great cities."