JERUSALEM, Israel - Senior Hamas and Islamic Jihad officials reportedly went underground after Wednesday's bus bombing in Jerusalem, shutting off cell phones and evacuating "security" facilities in the Gaza Strip.

Hamas declared a "state of emergency" in anticipation of an Israeli response to the bombing and to increased rocket and mortar attacks - more than 25 in the past four days - by Gaza-based Palestinians in southern Israel.

Israeli aircraft scored direct hits on smuggling tunnels, terrorist training sites and rocket launch pads early Thursday morning. No one was injured in any of the hits.

No group claimed responsibility for Wednesday's bombing, but Palestinian Authority security forces arrested two Islamic Jihad members in Jenin early Thursday, according to a statement released by the terror group.

"Palestinian security forces broke into the home of Jihad official Khaled Jaradat and arrested him. Other forces arrested organization official Terek Kaadan near his home," the statement read.

Both Hamas and Islamic Jihad justified Wednesday's bombing, which killed a 56-year-old British tourist and injured up to 40 others, while P.A. President Mahmoud Abbas and Prime Minister Salam Fayyad released statements condemning the attack.

---

The Jerusalem Post contributed to this report.