Mysql - Table lock error

I am experiencing some problems with table locking. I have locked certain number of table in transaction. LOCK TABLES t1 READ, t2 READ, t3 READ, t4 READ,t5 READ,t6 READ,t7 READ;

While reading its ok, but when I am trying to write/update to this tables it's showing the error Table 't1' was locked with a READ lock and can't be updated

But I never locked the table for write, I have to write to these tables with updated values.

My aim is I need to select and I need to update rows, while others should not interact with above tables until the process finished.

Much appreciated your solutions!