At least one man was injured Monday, medics told Ma'an, in what witnesses near the Gaza International Airport said was a volley of artillery fire from an Israeli tank operating near the Rafah border area.

Medics said teams were dispatched to the area to evacuate the wounded, while witnesses said ambulances were seen arriving at the airport, following the firing of several shells.

In a statement released early in the afternoon, the National Resistance Brigades said fighters operating east of Rafah fired Rocket-Propelled Grenades toward Israeli tanks. NRB is the armed wing of the Democratic Front for the Liberation of Palestine.

Spokesman of Gaza Strip’s ambulance and emergency services Adham Abu Salmiya confirmed that one man was moderately injured and evacuated to the Abu Yousif An-Najjar Hospital in Rafah.

An Israeli military spokeswoman said tanks operating as part of "routine activity along the security fence in the southern Gaza Strip" identified a "group of militants that had been involved in an number of terror attacks against IDF soldiers."

She said the tank fired a number of shells toward the group and "identified a hit."

The firing comes less than 12 hours after the death of a Palestinian militant in the northern Gaza Strip and the injury of two others in what witnesses told Ma'an was an Israeli airstrike.

AFP quoted officials saying the injuries were caused by Israeli tank artillery fire.

Al-Quds Brigades, the armed wing of the radical Islamic Jihad group, said one of its men, Abdelmajid Shahin, was killed and another was lightly wounded in the incident.

A second attack east of Gaza city was also reported around 9 p.m. on Sunday, with no injuries identified.

Israeli military officials said no such attack had taken place, but mentioned that Palestinian factions operating in the area had fired a mortar shell toward Israel.

The denial came after Hamas officials in the Gaza government released a statement saying Israeli officials were exaggerating reports of projectile from from the coastal enclave, and accused officials of fabricating reports in an attempt to gain international support for a new offensive against Gaza.

The reported projectile fire followed a string of Israeli air raids Saturday night targeting what the army described as militant training camps across the area.

One air strike wounded four people including a toddler, Palestinian officials and medics said.

Israeli Police spokesman Micky Rosenfeld said on Sunday that Israel's alert level had been raised in response to the renewed rocket fire and regional instability.

Israeli officials said that after the strikes a a mortar was fired into Israel from the central Strip, without causing casualties or damage.

A first set of air strikes on Saturday hit two Islamic Jihad camps, while a second raid targeted two camps belonging to the Izz Ad-Din Al-Qassem Brigades, the armed wing of Gaza's ruling Hamas movement, in the southern city of Rafah.

It was during the second raid that the four people including the child were wounded, Palestinian officials and medics said.

A third air strike blasted an Islamic Jihad facility west of Khan Younis, witnesses said.

The Israeli military said Saturday's attacks had "targeted a number of terror hubs... in response to recent rocket fire into Israel."

The air raids came after tensions rose along the Israel-Gaza border this week following clashes in which an Islamic Jihad gunman was killed and a rocket attack on the Israeli city of Beersheba hit a house but caused no casualties.

It was the first rocket to reach the city since the devastating offensive against Gaza between December 2008 and January 2009, prompting Prime Minister Benjamin Netanyahu to warn militants not to "test" Israel.

Hamas said in a statement on Sunday it wanted to avoid a new test of force with Israel.

"We are determined to continue a policy of national consensus with all the Palestinian factions," it said in a reference to instructions to observe a ceasefire.

Rosenfeld said on Sunday Israel's alert level had been heightened.

"The police examined the security situation and decided to raise the alert level on Israeli territory for a week," he said.

"The security examination was undertaken after the new Palestinian rocket fire on Sunday and because of the continued unrest in the Arab and Muslim world."

Israel often raises its security alert level in response to a perceived increase in the risk of attacks.

AFP contributed to this report