You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Dissolution_of_the_Soviet_Union

Context:
From April 20–23, 1989, pre-election meetings were held in Lviv for four consecutive days, drawing crowds of up to 25,000. The action included an one-hour warning strike at eight local factories and institutions. It was the first labor strike in Lviv since 1944. On May 3, a pre-election rally attracted 30,000 in Lviv. On May 7, The Memorial Society organized a mass meeting at Bykivnia, site of a mass grave of Ukrainian and Polish victims of Stalinist terror. After a march from Kiev to the site, a memorial service was staged.

Question:
Where did the strike take place?

eight local factories and institutions