incursion
n.a sudden attack or a small group of people entering a place where they are not welcome. It is often used to describe a military move into an enemy's territory.
n.a sudden, often violent, entry into a territory or area; a military attack or raid. Often implies a temporary or limited movement rather than a full-scale invasion.
“The army launched a small incursion into the enemy's camp.”
“The border patrol reported a sudden incursion of illegal vehicles across the river during the night.”
“While the initial incursion was met with heavy resistance, the strategic placement of the troops allowed for a swift and decisive withdrawal before reinforcements arrived.”
“The most brazen attack came in March, when Roland says some 30 to 40 settlers stormed the quarry site in a coordinated mass incursion.”
“Soldiers also detained three Palestinians amid a settler incursion in Burqa, east of Ramallah.”
From Middle English, borrowed from Old French, from Latin incursiō.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.