GAZA CITY, Gaza Strip (AP) — Israel has warned Gaza residents they will be risking their lives if they approach the border during a planned mass protest.

The army says in the leaflets dropped by jets Monday that it will "act against every attempt to damage the security fence or harm IDF soldiers or Israeli civilians."

Gaza's ruling Hamas says it expects tens of thousands to join Monday's march, suggesting a possible border breach. The march is part of a campaign to break Gaza's decade-old border blockade. It's also a protest against the inauguration Monday of a U.S. Embassy in contested Jerusalem.

Since March, 42 Palestinian protesters have been killed and more than 1,800 wounded by Israeli army fire.

With Israel and Hamas digging in, there has been concern about large numbers of casualties Monday.