A bus has exploded in Jerusalem. The number of casualties is unknown, but there are reports that people are being carried away on stretchers. The explosion came from a bomb left in a bag at a bus stop near the main entrance to Jerusalem, shattering windows in nearby buildings. It appears to be the first bus bombing in several years and comes amid rising tensions between Hamas militants and Israel. The BBC's Bethany Bell reports from Jerusalem.

Tensions have been running high since Israel announced plans to build 1,600 new homes in disputed East Jerusalem during a visit to Israel by Vice President Joe Biden last week. Secretary of State Hillary Clinton said Tuesday that ties between the U.S. and Israel remain strong, noting "we don't agree with any of our international partners on everything."

As President Obama wraps up his trip in Asia, news out of the Middle East is threatening to distract from whatever progress he might have made this past week on the international stage. Israel has announced plans to expand a Jewish district of Jerusalem captured in the 1967 war. The Palestinians have said this district belongs to their future state.

Isabel Kershner is a reporter for our partner The New York Times. She reported on the story, and she joins us from Jerusalem.