Peter Kenyon

Residents of the Syrian city of Hama are bracing for another day of shelling and shooting as the regime continues its military crackdown on the first Friday of Ramadan. Hama residents say they're trapped in their houses, often without electricity or water.

In a sharp escalation of violence in Syria, government troops Sunday moved into the central city of Hama, killing dozens, in a bid to regain control of a major hub of the country's opposition movement.

Iran says a scientist killed in Tehran over the weekend was not connected with the country's nuclear program, but the daylight killing and recent announcements by Tehran of nuclear advances have renewed scrutiny of the country's nuclear effort.

Iranian media said 35-year-old Darioush Rezai-Nejad was a promising graduate student. Officials speculated that his assailants — gunmen on motorbikes — may have confused him with a nuclear scientist with a similar name.

Iran says the killing of a young scientist Saturday was a "U.S.-Zionist terrorist act."

Darioush Rezai-Nejad, 35, was gunned down in Tehran on Saturday by assailants who also wounded his wife, according to state-run Iranian media.

A number of Iranian nuclear scientists have been attacked in recent years, but officials said in this case there may have been a mistake. Official media said Rezai-Nejad, a promising graduate student, may have been killed because his name is similar to another scientist, who does work on Iran's nuclear program.

The Arab Spring has largely bypassed Lebanon, but the new government may still be in jeopardy.

Growing unrest next door in Syria is seen as an imminent danger. It doesn't help that a key player in the new government is Hezbollah, the Shiite militia and party backed by the increasingly unpopular regime in Damascus. Nor does it help that four Hezbollah members are accused in the killing of a former Lebanese prime minister — a charge Hezbollah denies.