Israeli aircraft dropped leaflets over the Gaza Strip for the first time since the end of a 22-day assault more than two years ago.

The leaflets, dropped late Sunday and early Monday, written in Arabic and signed by the "Israel Defense Forces," warned residents not to come near the border with Israel in the northern part of the territory, witnesses said.

The leaflets warned citizens against approaching within 300 yards of the border. "Anyone approaching the buffer zone will put himself in danger," one leaflet read.

The step by Israel came after an escalation in violence along the border over the last two weeks, with militants -- believed to be from an extremist group known as Tawhid and Jihad --firing about a dozen rockets into Israel and Israel responding with airstrikes that have killed three people and wounded 10 others.

It marked the first leaflet drop by Israel since Operation Cast Lead in early 2009, heightening fears among Gaza residents about another military assault. In an attempt to calm the situation, Hamas Prime Minister Ismail Haniyeh called on the militants in Gaza to accept an immediate halt in rocket attacks against Israel. So far, the call by Hamas, which controls Gaza, has not been heeded.