• Israel's intelligence service has arrested dozens of Hamas members in the West Bank

·         Also Monday, Israeli aircraft struck a Palestinian rocket launching pad and an unidentified militant activity site in the Gaza Strip, in response to persistent rocket and mortar fire from the coastal territory, the military said.

·         Gaza militants launched 21 rockets and mortars into southern Israel earlier in the day, according to the military's count. No casualties were reported on either side.

·         Hamas violently took over Gaza in 2007 in bloody street battles from the rival Palestinian group Fatah.

·         In Hamas-controlled Gaza, militants fired volleys of rockets and mortars at southern Israel, triggering an Israeli airstrike.

·         Israel and much of the West deals with the Palestinian Authority, while shunning Hamas, labeling it a terror group due to its suicide bombings and other attacks on Israel that killed hundreds of civilians.

·         Israel's intelligence service has arrested dozens of Hamas members in the West Bank who had been setting up infrastructure for the militant Islamic group there, according to a statement Monday.

·         Military aircraft dropped leaflets over Gaza warning Palestinians to stay away from the border fence with Israel or risk drawing fire.

·         The hostilities threatened to undercut a brittle, informal truce that went into effect last week after the worst outbreak of violence between the two sides in months.

·         The leaflets also warned civilians not to cooperate with militants, dig smuggling tunnels or smuggle in weapons.

·         The Palestinian Authority, dominated by Fatah, has limited powers in the West Bank under Israel's overall security control and has launched its own crackdown against Hamas.

·         The Shin Bet said that 30 Hamas members were arrested near Ramallah, the West Bank's administrative center. It said they were setting up a Hamas network in the West Bank and were relaying information to the overseas leaders of the group, which is sworn to Israel's destruction. They were also setting up Hamas cells in West Bank schools, the statement said.

·         The statement said two of those arrested were involved in the murder of two Israeli soldiers by a Palestinian mob in 2000. The soldiers entered Ramallah by mistake and were taken to a police station, where they were tortured and then thrown out of a second-story window.