Is killing a aria2 process then resume the download(sftp) a safe action?

[JCYang]

Hi, I'm using aria2c to download list of files(via url file) regularly in linux.
I use -s16 and -x16 to maximize speed, from time to time, when most files are finished and one or two large ones are left downloading,
the speed will down to maybe 1/10 of the top that my link can reach.
There're .aria2 files next to the targets, is it safe to simply kill the still running aria2, and then resume by the same command(yes, I will remove all the finished links from the url files) to accelerate the whole thing?
Thanks.