Two people were wounded Thursday after an anti-tank missile exploded into a bus traveling in one of the communities surrounding the Gaza Strip.

Following the attack, 16 additional mortar shells were fired at Israeli towns in the western Negev, most of them hitting open areas.

Open gallery view Bus damaged by missile strike from Gaza which wounded two people, April 7, 2011. Credit: Ilan Assayag

Magen David Adom crew who arrived at the scene said that a 16-year-old boy was critically wounded as a result of the attack, and that the bus driver was moderately hurt by shrapnel wounds in his leg.

"The boy was lying on the ground bleeding. The bus driver was conscious and hysterical. The entire bus destroyed – it was a horrifying sight," said a member of the rescue service.

MDA said that the rescue services resuscitated the boy and later transferred him to the hospital. MDA also said the bus was nearly empty after dropping off school children and was carrying only the driver and the 16-year-old boy at the time of the attack.

Residents of communities near the site of attack were instructed by authorities to stay inside their homes in case the strikes at Israeli towns will continue.

Following the attack, the Israel Defense Forces quickly retaliated and launched both land and air strikes on Hamas targets in the Gaza Strip, the IDF spokesperson said, killing a 50-year-old man and wounding five others.

Defense Minister, Ehud Barak ordered the army to respond quickly and said he held the Hamas militant group, which rules Gaza, responsible for the violence. There was no claim of responsibility for the attack.

The strike came following several weeks of tension and mutual attacks along Israel's border with the Hamas-ruled Strip, with Israel Defense Forces aircraft striking smuggling tunnels in southern Gaza earlier Thursday.

On Tuesday, IDF tanks fired at and killed an armed Palestinian approaching the Gaza Strip's border with Israel on Tuesday, as three mortar bombs exploded in Israeli soil.

The incident took place after an IDF force spotted an armed Palestinian near the Erez crossing at the Strip's north, later directing tank fire to the spot. No injuries were reported from among the soldiers.

On Saturday, IDF planes struck a vehicle travelling at the south of the Gaza Strip, killing three Hamas operatives, one of them a top commander in Hamas' military wing.

An IDF Spokesperson stated that the three men were members of a terrorist cell that was "planning to kidnap Israelis over the upcoming Jewish holiday of Passover" in Israel and in the Sinai Peninsula, a popular spring tourist destination for Israelis.

The Palestinian Ma'an news agency identified the three as Ismail Labad and his brother Abdullah from Ash-Shati' refugee camp in the northern Gaza Strip, and military commander Muhammad Ad-Dayah from the Zaytoun neighborhood of Gaza City.

Ad-Dayah, 33, is considered to be a top Hamas military official. As a child he participated in the first intifada, later serving as the bodyguard of former Hamas chief Abdel Aziz Rantisi. Ad-Dayah also lost one of his eyes during an attempted mortar attack on a nearby settlement.

Hamas vowed vengeance against Israel in a statement Saturday, describing the strike as a crime and "serious escalation" of the recent violence, and vowed that Israel would "bear all the consequences." The militant group also called on the U.S. to stop the flow of financial aid to Israel.

Prior to the attack, Palestinian militants have fired rocket salvos into Israel, reaching as far as the major southern city Be'er Sheva, and Israel has carried out a series of air strikes.