Definition: In this task, a passage will be given and the goal is to identify an event from the passage. An event is defined as a single word representing something that happened, is happening, or may happen. An event can be factual or hypothetical, positive or negative, certain or uncertain. While most events are based on verbs, an event can also be based on a noun (ex. storm, snow, rainfall) or a copula verb (is, was, been, etc.). The event must not be a pronoun or an adjective. For noun events with multiple words, use the last word in the phrase as event.
Input: Passage: A major firefight broke out early Monday after nearly 200 militants crossed the border from Pakistan and attacked a border checkpost in the eastern Afghan province of Khost, police said. Five Taliban fighters and an Afghan militia soldier died in the hour-long exchange of fire, provincial police official Gul Dad said, adding that four Afghan nationals were arrested.

attacked