Multiple jobs are processing with one worker

I have an app built on laravel 5.1 which is using RabbitMQ for job processing. The worker command is as follows:

php artisan queue:work --queue=[queue-name] --daemon --tries=5

The issue which I am experiencing is that multiple jobs are getting processed at the same time even though I have only one worker for the queue. How and why is this happening? I have a table which tracks the status of the jobs and as per the table, the number of parallel processing jobs sometimes increase to 8 or 9. With one worker, this count is strange.

Note:

• My application has 3500-4000 jobs for processing daily
• The jobs are time consuming so dont know if this has something to do with the process timeout

via Chebli Mohamed