Thrissur: Tension prevailed at the Thrissur district collectorate on Tuesday afternoon as the police tried to block a march by a section of nurses, who are on an agitation demanding hike in wages.Police had to resort to caning as the agitating nurses tried to barge their way into the labour department office housed in the collectorate. The nurses affiliated to United Nurses Association (UNA) have decided to observe a ‘protest day’ in the district on Wednesday against the police action against the organisation leaders.UNA state president Shoby Joseph said only one-third of the nurses will report for duty on Wednesday. UNA will also serve a 15-day notice for indefinite strike to various hospitals in the district.The nurses are on strike for the last three months demanding a hike in wages for the nurses employed at Amala hospital and Jubilee Mission hospital. Several other hospitals have already agreed to increase wages after negotiating with UNA.However, the managements of Amala and Jubilee hospitals have not acceded to the demands, the UNA leaders allege. The UNA leaders had given complaints to the district labour officer against the management of those two hospitals. They alleged the labour officer had not even conducted an inspection based on the complaints, so far.UNA leaders also alleged that the labour officer was unwilling for conciliation talks even on Tuesday when the nurses took out a march. UNA alleged that some of the nurses’ leaders were injured in the police action. UNA leaders said the health minister has convened a conciliation talk at his chamber in Thiruvananthapuram on Saturday.